Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J1/00—Photometry, e.g. photographic exposure meter
  • G01J1/02—Details
  • G01J1/08—Arrangements of light sources specially adapted for photometry standard sources, also using luminescent or radioactive material
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
  • F21V9/40—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters with provision for controlling spectral properties, e.g. colour, or intensity
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S8/00—Lighting devices intended for fixed installation
  • F21S8/006—Solar simulators, e.g. for testing photovoltaic panels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V13/00—Producing particular characteristics or distribution of the light emitted by means of a combination of elements specified in two or more of main groups F21V1/00 - F21V11/00
  • F21V13/12—Combinations of only three kinds of elements
  • F21V13/14—Combinations of only three kinds of elements the elements being filters or photoluminescent elements, reflectors and refractors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V5/00—Refractors for light sources
  • F21V5/02—Refractors for light sources of prismatic shape
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
  • G01J3/02—Details
  • G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
  • G01J3/02—Details
  • G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
  • G01J3/0208—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
  • G01J3/02—Details
  • G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
  • G01J3/0216—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using light concentrators or collectors or condensers
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
  • G01J3/02—Details
  • G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
  • G01J3/0229—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
  • G01J3/02—Details
  • G01J3/10—Arrangements of light sources specially adapted for spectrometry or colorimetry
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
  • G01J3/12—Generating the spectrum; Monochromators
  • G01J3/14—Generating the spectrum; Monochromators using refracting elements, e.g. prisms
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/08—Mirrors
  • G02B5/0816—Multilayer mirrors, i.e. having two or more reflecting layers
  • G02B5/085—Multilayer mirrors, i.e. having two or more reflecting layers at least one of the reflecting layers comprising metal
  • G02B5/0858—Multilayer mirrors, i.e. having two or more reflecting layers at least one of the reflecting layers comprising metal the reflecting layers comprising a single metallic layer with one or more dielectric layers
  • G02B5/0866—Multilayer mirrors, i.e. having two or more reflecting layers at least one of the reflecting layers comprising metal the reflecting layers comprising a single metallic layer with one or more dielectric layers incorporating one or more organic, e.g. polymeric layers
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
  • H02S50/00—Monitoring or testing of PV systems, e.g. load balancing or fault identification
  • H02S50/10—Testing of PV devices, e.g. of PV modules or single PV cells
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/26—Testing of individual semiconductor devices
  • G01R31/2607—Circuits therefor
  • G01R31/2632—Circuits therefor for testing diodes
  • G01R31/2635—Testing light-emitting diodes, laser diodes or photodiodes
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/04—Prisms

Definitions

• the invention relates to a spectral shaper illumination device and a method for providing a tunable spectrally shaped focused spectrally split beam modulated in intensity and/or in a wavelength range with respect to the light source. Furthermore, the invention refers to a method for optical spectroscopic characterization of optical and/or optoelectronic materials and/or devices using said spectral shaper illumination device. Moreover, the present invention refers to an optical metrology system comprising the spectral shaper illumination device.
• the invention is therefore of interest for the optical and/or optoelectronic industries and for the optical metrology industries.
• Illumination sources for optical characterization and metrology systems usually have demanding operational requirements and tight tolerance. Some applications may need a narrowband light source with continuous tunability of the central wavelength and bandwidth, while others may need broadband illumination with a specific spectral distribution.
• characterization of a solar cell device requires a set of experiments.
• the first one is the measurement of the power conversion efficiency using a solar simulator as illumination source, in which the spectrum is broadband and adjusted to the AM1.5 standard for terrestrial applications, or AMO for space applications (or others for indoor applications, diffuse light illumination etc.).
• the photocurrent of the solar cell under illumination is measured as a function of voltage to calculate the power conversion efficiency.
• a typical measurement of the recombination occurring in a solar cell requires repeating the above for an illumination that has the same spectral shape than the AM1 .5, but with an integrated intensity (in units of suns) spanning several orders of magnitude (typically from O.OIx to 1.5x AM1.5).
• the other basic measurement is that of the external quantum efficiency (EQE), which is the measurement of the photocurrent under monochromatic wavelength illumination, typically in short circuit conditions. The measurement is repeated many times for different central wavelengths in the range between 350 nm and 1100 nm.
• EQE external quantum efficiency
• Other types of characterization include that of stability (measurements over time in which often the UV part of the spectrum is filtered), characterization under concentrated light, and characterization of tandem geometries. Most of these measurements require independent apparatus, mainly due to the characteristics of the illumination device, since, from an electronic point of view, the measurement is almost always the same (a photocurrent vs voltage curve).
• broadband illumination is typically obtained using lamps (e.g. halogen, xenon arc, etc.), arrays of light emitting diodes (LEDs), phosphorescent sources couple to monochromatic excitation (e.g. UV LED) or supercontinuum lasers.
• Narrowband illumination is obtained by using LEDs, lasers, or by spectrally filtering a broadband source.
• Tuning the central wavelength of a narrowband illumination device is normally obtained by coupling a broadband source to a monochromator. Effectively, a monochromator acts as a band pass optical filter.
• special filters are designed. Typically, the latter are based on distributed Bragg reflector filters, which are typically static (i.e. one filter provides one spectrum) and can suffer from limited wavelength range due to diffraction of higher orders.
• LED arrays are particularly useful to produce different broadband spectra (e.g. AMO and AM1.5G).
• AMO and AM1.5G broadband spectra
• LED illumination has several intrinsic limitations, such as poor spectral resolution (typically, LEDs used in this type of devices have FWHMs of tenths of nanometers), need for refrigeration (for medium/high power illumination requiring temporal stability) and, importantly, non-linearity response with current, which strongly limits the dynamic range of the illumination source.
• a tunable filter uses a grating to spatially split the colours from a broadband source, a spatial filter located at the focal point to modify the intensity at given positions of the spectrally splitted beam, and then a condensing grating to spatially mix the different colours back into a single, homogeneous beam [US10422508B2],
• This filtering element while very interesting, still has some limitations.
• the first one is that the use of gratings to disperse light results in a limited spectral range available before higher orders appear in the spectrum (e.g. typically the range is limited from a first wavelength Xi to a maximum of a wavelength 2x Xi).
• a system form by two gratings would tend to loose a significant fraction of light intensity.
• the outcome of the aforementioned setup is a homogeneously distributed beam and not a spectrally spilt beam. While this can be useful for some applications, a spectrally split beam is required for measurements such as multijunction photovoltaics based on the spectrally split concept.
• the present invention refers to a spectral shaper illumination device for providing a tailored/tunable spectrally shaped focused spectrally split beam, which is suitable for optical spectroscopic characterization of optical and/or optoelectronic materials and devices and for metrology systems.
• a first aspect of the invention refers to a spectral shaper illumination device for providing a tunable spectrally shaped focused spectrally split beam (herein the illumination device of the present invention) comprising
• a light source configured to provide a beam of wavelengths between 300 nm and 1200 nm
• a concave mirror configured to receive the spectrally split beam and to focus said spectrally split beam into a focal point, thereby providing a focused spectrally split beam
• a first filtering element selected from a plurality of motorized guillotines or an LCD screen controlled by control means and configured to receive the focused spectrally split beam and to filter a range of wavelengths from the focused spectrally split beam, thereby providing a spectrally shaped focused spectrally split beam
• a second filtering element selected from a shaped shadow mask, an LCD screen, a DMD array, a mechanical light filtering element, a pixelated filter or an apodization filter and configured to receive the focused spectrally split beam and to filter the intensity of a range of wavelengths of the focused spectrally split beam, thereby providing a spectrally shaped focused spectrally split beam,
• the term “spectrally split beam” refers to a beam that is splitted in its composing wavelengths alone on XY plane.
• the spectrally split beam is a beam comprising a set of stripes, each stripe with a different colour and one stripe next to the other.
• the light source providing the beam of wavelengths between 300 nm and 1200 nm is preferably providing a collimated beam of wavelengths between 300 nm and 1200 nm.
• the light source providing the beam of wavelengths between 300 nm and 1200 nm is selected from a xenon arc or halogen lamp, arrays of light emitting diodes (LEDs), or a supercontinuum laser.
• a refractive element is used in the illumination device of the present invention to separate the beam of wavelengths between 300 nm and 1200 nm into a spectrally split beam.
• the refractive element is selected from at least a prism or a Fresnel lens.
• the refractive element is a double Amici prism having a mirror symmetry along its mid plane. It is advantageous to use said double Amici prism because it preserves the incoming direction and position of the collimated beam, simplifying the configuration of the illumination device of the present invention.
• the concave mirror with a customized curvature, rather than undoing the dispersion of the Amici prism, is introduced solely for the purpose of focusing the beam exiting the Amici prism but keeping the spectral splitting of the beam.
• the beam size (which is proportional to the wavelength separation) can be tuned by the size and position of the mirror, and by the design of the focal length of the mirror. The larger the mirror and prism/mirror distance, the higher the color separation.
• the curvature of the concave mirror matches the output of the refractive element to focus all wavelength components of the spectrally split beam into a focal point, maintaining the spectrally split beam.
• a further preferred embodiment of the illumination device of the present invention refers to the concave mirror which comprises a polyethylene terephthalate glycol (PETG) sheet, a layer of silver (Ag) on the top of the PETG sheet and a layer of lithium fluoride (Li F) on the top of the Ag layer.
• PETG polyethylene terephthalate glycol
• Ag silver
• Li F lithium fluoride
• the first filtering element is more proximate to the concave mirror than the second filtering element or the second filtering element is more proximate to the concave mirror than the first filtering element.
• the placement of the first or the second filtering element closer to the concave mirror does not influence the output spectrally shaped focused spectrally split beam produced by the illumination device.
• the two filtering elements, the first filtering element and the second filtering element are a single LCD screen.
• an LCD screen it is possible to filter a range of wavelengths from the focused spectrally split beam and simultaneously filter the intensity of a range of wavelengths of the focused spectrally split beam.
• the main advantage of this preferred embodiment is the use of only one filtering device to filter by intensity and by wavelength.
• said device further comprises a light pipe, which is essential for homogeneous areal illumination, said light pipe is placed after the vertical cylindrical lens and configured to receive the tunable spectrally shaped focused spectrally split beam and to homogenize spatially the tunable spectrally shaped focused spectrally split beam.
• the light pipe comprises a diffusion element configured to introduce randomness in the direction of the tunable spectrally shaped focused spectrally split beam, which improves the homogeneity of the beam in the whole area of illumination.
• the spectral shaper illumination device of the present invention is capable to produce almost any spectrum on demand, particularly suitable for the optical spectroscopic characterization of materials and devices e.g. for photovoltaic applications.
• the spectral shaper illumination device provides a tailored/tunable spectrally shaped focused spectrally split beam modulated in intensity and/or in a wavelength range with respect to the light source:
• a beam spatially split in its wavelength components a unique capability of the invention for illuminating lateral tandem (rainbow) solar cells.
• the spectral shaper illumination device of the present invention is therefore of interest for the optical and/or optoelectronic industries and for the optical metrology industries. Particularly, for the optical spectroscopic characterization of optical and/or optoelectronic materials and devices for photovoltaic (PV) applications like conventional solar cells but specifically for rainbow-type solar cell tandems, agrovoltaics, indoor PV, building integrated PV (windows, sunshades, etc.). Another application of the spectral shaper illumination device of the present invention is, for example, in photo-catalysis, for the characterization of light absorbers, or for degradation studies.
• PV photovoltaic
• the illumination device of the present invention provides a tailored/tunable spectrally shaped focused spectrally split beam which
• Is highly tunable in terms of spectrum (AM1 .5, AMO, but also, different luminaries as those used indoors, for BIPV, or for agrovoltaic applications, tunable low/high pass filter for spectral splitting photovoltaics and stability measurements, etc.).
• a second aspect of the present invention relates to a method for producing a tunable filtered focused spectrally split beam using the spectral shaper illumination device of the present invention (herein the first method of the invention) as disclosed above, said method comprising the following steps: a) providing a beam of wavelengths between 300 nm and 1200 nm by means of a light source, b) separating the beam obtained in step (a) into a spectrally split beam by means of a refractive element, c) focusing the spectrally split beam obtained in step (b) into a focal point by means of a concave mirror, d) filtering the focused spectrally split beam obtained in step (c) by means of first filtering element and/or the second filtering element, and
• the main advantage of the first method of the present invention is that is possible to provide a tailored/tunable spectrally shaped focused spectrally split beam.
• Step (d) of the first method of the present invention allows the filtering by intensity and/or by wavelength.
• the provided beam of step (a) is a collimated beam. This improves the separation of colors by the refractive element, increasing the spectral resolution of the system (e.g. the sharpness of the high/low band threshold).
• step (d) refers to the filtering of the focused spectrally split beam by means of first filtering element and the second filtering element, thereby obtaining in step (e), a tunable spectrally shaped focused spectrally split beam by intensity and by wavelength, which is advantageous for characterization of rainbow solar cells.
• said method further comprises a step of homogenizing spatially the tunable spectrally shaped focused spectrally split beam by means of a light pipe thereby obtaining a spatially and spectrally homogeneous beam profile with the tunable spectrally shaped focused spectrally split beam, this is a spatially and spectrally homogeneous beam profile with the predefined spectrum derived from the filtering process.
• the first method of the invention further comprising a step of introducing randomness in the direction of the tunable spectrally shaped focused spectrally split beam by means of a diffusion element thereby obtaining a spatially and spectrally homogeneous beam profile
• the diffusion element is hold in the light pipe and improves homogeneity.
• a third aspect of the present invention refers to a method for optical spectroscopic characterization of optical and/or optoelectronic materials and/or devices (herein the second method of the invention) characterizing using the spectral shaper illumination device of the present invention as described above characterized in that it comprises the following steps: i) providing a tunable spectrally shaped focused spectrally split beam or a spatially and spectrally homogeneous beam profile using the first method as described above, wherein the tunable spectrally shaped focused spectrally split beam or the spatially and spectrally homogeneous beam profile is directed to the optical and/or optoelectronic material and/or the device, ii) measuring the response of the optical and/or optoelectronic material and/or the device to the tunable spectrally shaped focused spectrally split beam or the spatially and spectrally homogeneous beam profile obtained in step (i) by means of a current/voltage sensing/meter device
• This second method refers to the optical spectroscopic characterization of optical and/or optoelectronic materials and/or devices.
• optical and/or optoelectronic materials refers herein to substances used to manipulate the flow of light by reflecting, absorbing, focusing or splitting an optical beam. The efficiency of a specific material at each task is strongly wavelength dependent.
• Optical and/or optoelectronic materials refer to compounds in solution, bulk or deposited or grown as thin films, for which their optical and/or optoelectronic properties are one of their distinctive features or functionalities. These may include organic, inorganic, oxide and hybrid semiconductors; photochromic, electrochromic and thermochromic materials; phase change materials; photocatalytic, photosynthetic and photovoltaic materials; organic and inorganic dyes; materials exhibiting gradients in relevant parameters (e.g.
• biological systems e.g. parts of plants, cyanobacteria, etc.
• chiral systems including pharmacologic compounds
• plasmonic nanoparticles self-assembled monolayers
• optical coatings e.g. anti reflective coatings
• optical and/or optoelectronic device refers herein to an apparatus or systems that processes an optical beam (light waves or photons).
• Optical and/or optoelectronic device refers to apparatus or systems for which the optical properties of one or more of the elements play a fundamental role in their operation. These may include photovoltaic devices in general, solar cells, photodetectors, photodiodes, phototransistors, light emitting diodes, flat screens, luminescent devices, luminaires, solid state lasers, photochromic devices, electrochromic devices, thermochromic devices, smart windows, photonic and plasmonic devices, photochemical cells, radiative cooling systems, optical telecommunication devices, etc.
• steps (i) and step (ii) are repeated and the spatially and spectrally homogeneous beam profile is differently filtered by means of the first and/or the second filtering element in each repetition.
• the optical and/or optoelectronic device is a solar cell, more preferably a multijunction solar cell.
• the last aspect of the present invention refers to an optical metrology system comprising the spectral shaper illumination device of the present invention as described above.
• Optical metrology is the science and technology concerning measurements with light, therefore the term “optical metrology system” refers herein to an apparatus or a device which is used for measuring with light, herein the light is provided by the spectral shaper illumination device of the present invention.
• Figure 1 shows the spectral shaper illumination device (1) of the present invention comprising
• Figure 2 is an example of four different target spectra (dashed) and the corresponding measured output spectra (solid). The four spectra are spectrally evaluated (bottom panel) following the ASTM E927-10 standards.
• Figure 3 shows the output spectrum as a function of the position of one of the guillotine elements of filtering element (7).
• Figure 4 shows the spectra of cards exhibiting a slit-like shape, from number 5 to number 30 of the filtering element used for calibration of the filtering element slits system (8).
• Figure 5 shows the normalized integrated power density transmitted as a function of slit height, being each slit obtained by a different card with different shadowing area (8).
• Figure 6 shows the effect of beam input light width and collimation on spectral resolution, normalized intensity of (a) 650, (b) 550 and ⁇ 425 nm light as a function of the relative motor position for a red sweep made with filtering element (as shown in Figure 4) when the input light is directly the output of the Xenon lamp (normal, solid line), the Xenon lamp with an added mask that reduces the width of the input beam (slit, dash-dot line) and the xenon lamp with extra optical treatment that improves collimation of light (collimated, dotted line).
• Figure 7 compares the organic solar cell performance measured with illuminated device with AM1.5G mask and standard Xenon lamp solar simulator, (a) Top panel: JV curve for one cell of each material measured under illuminated device (dashed) and a AAA solar simulator based on a Xenon lamp (solid), (b) Bottom panel: box plot of illuminated device measured IV parameters for three different materials (PTB7-Th:Y6, PTQ10:Y6 and P3HT:PCBM) normalized with the Xenon lamp measurement.
• Figure 8 is a representative external quantum efficiency (EQE) of the organic solar cells measured in Figure 7.
• Figure 9 is an example of a measurement made with the spectral splitting mode with both filtering elements (7, 8)
• Figure 10 is an example of extra information that can be extracted from a spectral splitting mode measurement as in Figure 8.
• EQE external quantum efficiency
• Solid line is the external quantum efficiency (EQE) measured with a specific equipment for this kind of measurements.
• Figure 1 shows an illumination device (1) for providing a tunable filtered focused spectrally split beam (11) or a spatially and spectrally homogeneous beam profile (13) comprising
• an incoming collimated beam light from a Xenon lamp (2) passes through a double Amici prism (3) that separates the beam (2), only along one plane (X-Y plane), into its composing wavelengths.
• the main advantage of the double Amici prism (3) compared to any other type of prism rely on the fact that, due to the mirror symmetry along the mid plane of the prism, the paraxial incident beam has a wavelength (central wavelength) which preserves the incoming direction and position of the beam (2), facilitating the geometric design.
• the spectrally split beam (4) is forced to travel a certain distance to guarantee a correct spatial wavelength separation to attain the desired wavelength resolution.
• the distance is about 30 cm.
• the spectrally split beam (4) is reflected by a customized curvature silver mirror (5) that corrects the divergence applied by the prism (3) to unify the spectrum again into an illumination spot, reconcentrating the light in the X-Y plane.
• this mirror (5) was designed and produced using a 3D printed polymeric structure with the calculated curvature and a surface covered by evaporated silver-coated 1 .5 mm thick rectangular piece of PETG. The curvature was customized to have 35-40 cm.
• the mirror (5) finished PETG 0.5 mm thick sheets was clamped onto the custom curvature piece with a 3D printed adapter.
• the PETG sheet completely conformed to the custom curvature when bolting it to the 3D printed piece.
• This entire assembly was placed in the thermal evaporator, and a layer of Ag followed by a layer of LiF were deposited.
• the thick layer of Ag was the main reflective layer, acting as a first surface mirror, while the thin layer of LiF provided corrosion resistance to the Ag layer without significantly affecting the spectrum.
• An advantage of using a thin inexpensive PETG sheet is that, if anything happens to the mirror, we just need to replace the sheet and re-evaporate, without having to 3D print the custom curvature mirror backing again. Due to inaccuracies in the divergence measurements, the mirror (5) focus was not a perfectly narrow line, but rather a 7 mm wide strip. However, since the beam required further colour-remixing to correct for directionality inhomogeneities, the spot size was not a significant limitation. We further added a lid to the mirror (5) so that it is protected from debris and accidental contact since as a first surface mirror, it is incredibly sensitive to scratching and finger grease.
• Two filtering elements (7, 8) were placed in the beam’s path (6) before it converged to a focal point.
• This filtering element (7, 8) take advantage of the spatial separation of the different wavelength components of the focused spectrally split beam (6) to shape the output spectrum (9). To do so, the filtering element (7, 8) blocks light (6) at certain positions on the plane perpendicular to the central wavelength propagation. In that plane, one can define two orthogonal directions corresponding to the spectrally separated light (wavelength) and the height of the light beam (intensity). In that way, by varying the light (6) that is transmitted in the intensity direction at different parts of the wavelength direction, it is possible to tune the output spectrum on demand (spectral shaping).
• the other filter element (7) implemented in our setup is composed of two guillotines activated by motors that cuts the spectrally split beam (6) from both directions, producing the effect of a tunable high pass, low pass or band pass filters.
• This filter element (7) allows the selection of a beam (6) with specific wavelengths.
• a cylindrical lens (10) that concentrates the beam along one of the axes (Z axis in Fig. 1) ensures minimal light losses and provides a tight focus on to the next optical element along the vertical direction.
• the focal length of this lens (10) is designed to match with the focal of the mirror (5) in the perpendicular direction, to be on focus on both directions.
• a compliant 3D printed fixture that can accommodate a certain degree of deflection, returning to its original position after the force is removed.
• This compliant fixture was fully 3D printed using a combination of flexible (NinjaFlex TPU) and rigid (PLA) filament, with a specific shape that allows for some deflection in the XZ plane, and greater deflection (around 1 cm) on the Y direction, along the light pipe (12).
• a diffusing element (12a) is used in front of a homogenizing light pipe (12), where the input beam of the light pipe (11) is placed in the spectral convergence point.
• the diffusing element (12a) introduces significant randomness in the direction of the incoming light (11) and the homogenizing light pipe (12) gives out an improved homogeneous area of illumination (13), both spectrally and intensity wise.
• the final area of illumination (13) is directly proportional to the diameter of the light pipe (12).
• Our current implementation provides a significant homogeneous area of illumination on the order of 50 mm 2 (corresponding to a 4 mm inradius hexagon).
• the standard procedure is a measurement of the J-V curve under AM 1.5G 1000 l/l/nr 2 (corresponding to 1 Sun) from which the solar cell parameters (open circuit voltage, ⁇ /oc; short circuit photo-current density, Jsc', fill factor, FF, and power conversion efficiency; PCE) can be extracted.
• the solar cell parameters obtained when the solar cell is illuminated with the illumination device equipped with the AM1.5G 1 Sun mask are compared with the ones measured using a AAA Xenon lamp solar simulator (SAN-EI Electric, XES- 100S1).
• Figure 2 is an example of four different target spectra (dashed) and its corresponding output spectra (sold). The four spectra are spectrally evaluated (bottom panel) following the ASTM E927-10 standards.
• Figure 3 is an example of the effect of one of the motorized guillotines of the filtering element (7).
• the spectra shown corresponds to the output spectrum as a function of the position of one of the guillotine elements of filtering element (7).
• Figure 4 shows the spectra through cards with the shape of slits (8) and located at different positions in order to select different spectral regions. Particularly, Figure 4 shows from number 5 to number 30 of the filtering element used for calibration of the filtering element slits system (8). The shown spectra are used as basis of a linear combination to produce the desired spectrum with the filtering element (8), for example for the spectra showed in Figure 2.
• Figure 5 shows the normalized integrated power density transmitted as a function of slit height.
• the measured spectra were integrated along the slit peak, and its total power density normalized with the full slit spectrum is plotted as a function of the slit height, which is decreased linearly from top and bottom of the slit, for slits in the blue, green and red regions of the spectrum (data points).
• the ideal homogeneous distribution (dotted line) is plotted as reference. The data points are above the ideal homogeneous distribution, indicating that the spectrum along the intensity direction of the slit is concentrated in the center.
• Figure 6 shows the effect of beam input light width and collimation on spectral resolution.
• Figure 7 compares the OSC performance measured with illuminated device (1) with AM1.5G mask (8) and standard Xenon lamp solar simulator,
• Top panel JV curve for one cell of each material measured under illuminated device (dashed) and Xenon lamp (solid).
• Bottom panel box plot of illuminated device measured JV parameters for three different materials (PTB7-Th:Y6, PTQ10:Y6 and P3HT:PCBM) normalized with the Xenon lamp measurement.
• Each material boxplot comprises four different cells with different thickness and overall PCE.
• Figure 8 is a representative external quantum efficiency (EQE) of the organic solar cells measured in Figure 7.
• Figure 9 is an example of a measure made with the spectral splitting mode, wherein both filtering elements (7, 8) are filtering the focused spectrally split beam at the same time.
• the result is a kind of measuring that simulates the light that two different cells would receive under spectral splitting geometry.
• the results shown in Figure 9 are the solar cell performance parameters as a function of the part of the spectrum that each cell receives.
• Figure 10 is an example of extra information that can be extracted from a spectral splitting mode measurement as in Figure 8.

Landscapes

• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Nonlinear Science (AREA)
• Optics & Photonics (AREA)
• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Spectrometry And Color Measurement (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Photovoltaic Devices (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=86226624

Family Applications (1)

Country Status (2)

Citations (7)

Family Cites Families (1)

• 2022
  • 2022-05-23 ES ES202230437A patent/ES2956835B2/es active Active
• 2023
  • 2023-04-14 WO PCT/EP2023/059810 patent/WO2023227290A1/en unknown

Patent Citations (7)

Non-Patent Citations (3)

Also Published As

Similar Documents

Legal Events