CN214672614U - Four-end laminated perovskite solar cell based on silicon quantum dot concentrator - Google Patents

Abstract

The utility model relates to a four end stromatolite perovskite solar cell based on silicon quantum dot concentrator, include: silicon quantum dot concentrators (SiQD-LSCs) and Perovskite Solar Cells (PSCs); the perovskite solar cell is arranged below the silicon quantum dot concentrator; the silicon quantum dot concentrator consists of a nano porous antireflection film, a front quartz plate, a PMMA ring and a rear quartz plate; the upper surface of the front quartz plate is uniformly attached with a nano porous antireflection film; an octadecylene suspension layer is formed among the front quartz plate, the PMMA ring and the rear quartz plate; silicon battery pieces are adhered to the peripheral edges of the silicon quantum dot concentrator; the silicon cell plate is electrically connected with the perovskite solar cell. The utility model has the advantages that: the four-end laminated solar cell is provided, so that the efficiency and the ultraviolet stability of a device can be improved; compared to a single homogeneous PSC device, SiQD-LSC/PSC tandem solar cells enable significant improvements in efficiency (PCE) and uv stability.

Description

Four-end laminated perovskite solar cell based on silicon quantum dot concentrator

Technical Field

The utility model belongs to the solar cell field especially relates to a four end stromatolite perovskite solar cell based on silicon quantum dot concentrator (SiQD-LSC).

Background

In recent years, solution-type Perovskite Solar Cells (PSCs) have made great progress in achieving high energy conversion efficiency (PCE), which has been promoted from 3.8% in 2009 to 25.5% in 2021. Meanwhile, PSCs represent a great potential in reducing manufacturing costs compared to conventional crystalline silicon solar cells. Although PSCs have the advantages of high efficiency and low cost, their relatively low device lifetime has become a key issue before commercialization. One aspect of instability of PSCs is due to uv irradiation.

As an additional layer to the package, luminescent down-conversion two-dimensional devices are typically used to convert the ultraviolet portion of the solar radiation into visible light that is less harmful to the PSC device and more conducive to photoelectric conversion. Such a down conversion device is particularly important for PSCs containing a titanium oxide electron conversion layer because the interface of titanium oxide and a perovskite layer generates photocatalytic recombination under irradiation of ultraviolet rays, thereby affecting the conduction of electrons. In general, luminescent down-conversion materials need to have high ultraviolet absorptivity and high visible light absorptivity. For example, a europium-doped rare earth material film can be plated on the non-conductive surface of fluorine-doped tin oxide (FTO) glass of PSC to selectively absorb ultraviolet light while boosting the PCE by 15%. On the other hand, luminescent carbon quantum dots and lanthanide series multi-metal oxide salt can be added into the mesoporous titanium dioxide layer, so that the stability and efficiency of the mesoporous titanium dioxide layer are improved. In addition to the light emitting down-converter, an anti-reflective coating (ARC) may also be applied to the encapsulation of the solar cell to reduce the loss of incident light from the surface due to reflection by reducing the effective refractive index of the air side encapsulation surface. For a traditional silicon solar cell without an anti-reflection film, the loss of incident light is as high as 35-36%. Thus, including inorganic materials, e.g. SiO₂MgF2 and TiO₂The anti-reflection film is plated on the surface of the packaging glass of the silicon-based photovoltaic cell. On the other hand, the light incidence rate can be effectively improved by etching the surface of the crystalline silicon to form the light capture structure. For PSC devices, the design concept of the anti-reflection structure is mainly focused on the encapsulation layer, since the performance of the perovskite layer is susceptible to micro-machining techniques (e.g., etching). For example, disordered micro-pyramid structures made from Polydimethylsiloxane (PDMS) materialThe thin film is coated on the non-conductive surface of the FTO glass of the PSC, and the absorption rate of light is improved by 1.6 times on the premise that the electrical properties of the PSC are stable.

Another approach to mitigate the effects of ultraviolet light while improving photovoltaic efficiency is to incorporate a solar cell in a stacked configuration. Typically, the upper solar cell of the tandem structure absorbs short wavelength light from the solar radiation, while the remaining long wavelength light will be absorbed by the lower cell. In recent years, the study of a large number of perovskite-based tandem cell devices (mainly comprising three structures of perovskite/silicon, perovskite/GIGS thin film and perovskite/perovskite) proves that the overall PCE of the tandem solar cell is higher than that of any single device in the tandem structure. However, with respect to PSC, other band gap modulation based stacked optical devices that can be used as an upper layer solar cell have been still rarely developed.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the not enough among the prior art, provide a four end stromatolite perovskite solar cell based on silicon quantum dot concentrator.

The four-terminal laminated perovskite solar cell based on the silicon quantum dot concentrator comprises: silicon quantum dot concentrators (SiQD-LSCs) and Perovskite Solar Cells (PSCs); the perovskite solar cell is arranged below the silicon quantum dot concentrator; the silicon quantum dot concentrator consists of a nano porous antireflection film, a front quartz plate, a PMMA ring and a rear quartz plate; the upper surface of the front quartz plate is uniformly attached with a nano porous antireflection film; an octadecylene suspension layer is formed among the front quartz plate, the PMMA ring and the rear quartz plate; silicon battery pieces are adhered to the peripheral edges of the silicon quantum dot concentrator; the silicon cell plate is electrically connected with the perovskite solar cell.

Preferably, when an air gap is arranged between the perovskite solar cell and the silicon quantum dot concentrator, the width of the air gap is 0.2-2 mm; when no air gap is arranged between the perovskite solar cell and the silicon quantum dot concentrator, the original air gap position is filled with filling materials.

Preferably, the filler material is mirror oil.

Preferably, the perovskite solar cell is formed by connecting a plurality of sub-cells in series, and the sub-cells are made of perovskite type metal halide semiconductors; and the perovskite solar cell is sealed between two pieces of glass by butyl rubber, and the thickness of the packaging glass is 2.2-3.2 mm.

Preferably, the silicon cell pieces are adhered to the peripheral side edges of the silicon quantum dot concentrator through epoxy resin; the silicon cell plate and the perovskite solar cell are electrically connected in parallel.

Preferably, the nano-porous antireflection film is made of polymethyl methacrylate (PMMA); the octadecene suspension is filled with octadecene suspension layer by layer; the thickness of the front quartz plate is 0.1-10 mm, the thickness of the PMMA ring is 0.1-10 mm, and the thickness of the rear quartz plate is 0.1-10 mm.

The utility model has the advantages that:

the utility model provides a four-end laminated solar cell, which can improve the efficiency and ultraviolet stability of the device; compared to a single homogeneous PSC device, SiQD-LSC/PSC tandem solar cells enable significant improvements in efficiency (PCE) and uv stability.

Drawings

FIG. 1 is a 3D block diagram of a four-terminal stacked perovskite solar cell based on a silicon quantum dot concentrator;

in FIG. 2, A is a SiQD suspension (1.08mg mL)^-1) Absorption spectra and PL spectra in ODE; FIG. 2, B is a graph of the reflectance spectra of a single quartz plate and a quartz plate coated with PMMA nanoporous ARC;

a, B in FIG. 3 is the transmitted spectra of pure LSC and SiQD-LSC with different concentrations of SiQD; in FIG. 3, C is the absorption spectra of SiQD-LSC (solid line) and SiQD (dotted line) with different concentrations of SiQD; d in FIG. 3 is SiQD-LSC (SiQD concentration 1.08mg mL)^-1) Graph of the ratio of SiQD to LSC by different concentrations of SiQD under 365nm uv irradiation.

FIG. 4A is a schematic diagram of a PSC device structure; b is a real graph of the PSC; c is a schematic drawing of a silicon photovoltaic sheet bonded to the side edges of the SiQD-LSC by epoxy and placed in front of the PSC;

in FIG. 5, A, B and C are at 365nm (2.214mW cm)^-2)、465nm(2.207mWcm^-2) And 525nm (2.212mW cm)^-2) Under the irradiation of the LED, the LED emits light,EQE schematic of SiQD-LSC, rear PSC and a combination of both; d, E and F are xenon lamps (8.109mW cm)^-2) Irradiating SiQD-LSC, rear PSC and PCE combined with the SiQD-LSC; the dashed lines in C and F in FIG. 5 represent the EQE and PCE schematic diagrams of a single PSC under 365nm, 465nm and 525nm, respectively, and a single PSC under xenon lamp;

in FIG. 6, A, B and C are at 365nm (2.214mW cm)^-2)、465nm(2.207mW cm^-2) And 525nm (2.212mW cm)^-2) EQE schematic of SiQD-LSC, rear PSC and combinations of both under LED illumination; in FIG. 6, D, E and F are xenon lamps (8.109mW cm^-2) PCE schematic of SiQD-LSC, rear PSC and a combination of both under irradiation.

Description of reference numerals: a nanoporous anti-reflection film 101, a front quartz plate 102, a PMMA ring 103, a rear quartz plate 104, a perovskite solar cell 105, an octadecene suspension layer 106, a silicon cell 107, perovskite 2, carbon 3, an electrode 4, dense TiO 2₂ 5、TiO ₂6. Zirconium oxide ZrO₂7. FTO 8, glass 9 and a silicon quantum dot concentrator 10.

Detailed Description

The present invention will be further described with reference to the following examples. The following description of the embodiments is merely provided to aid in understanding the invention. It should be noted that, for those skilled in the art, the present invention can be modified in several ways without departing from the principle of the present invention, and these modifications and modifications also fall into the protection scope of the claims of the present invention.

Example one

An embodiment of the present application provides a four-terminal stacked perovskite solar cell based on a silicon quantum dot concentrator as shown in fig. 1 and 4, including: silicon quantum dot concentrators 10 (SiQD-LSCs) and perovskite solar cells 105 (PSCs); the perovskite solar cell 105 is placed below the silicon quantum dot concentrator 10; the silicon quantum dot concentrator 10 consists of a nano porous anti-reflection film 101, a front quartz plate 102, a PMMA ring 103 and a rear quartz plate 104; the upper surface of the front quartz plate 102 is uniformly attached with a nano-porous antireflection film 101; wherein a layer 106 of octadecene suspension is formed between the front quartz plate 102, the PMMA ring 103 and the rear quartz plate 104; silicon cell sheets 107 are adhered to the peripheral edges of the silicon quantum dot concentrator 10; the silicon cell 107 and the perovskite solar cell 105 are electrically connected.

When an air gap is arranged between the perovskite solar cell 105 and the silicon quantum dot concentrator 10, the width of the air gap is 0.2-2 mm; when no air gap is provided between the perovskite solar cell 105 and the silicon quantum dot concentrator 10, the original air gap position is filled with mirror oil or the like.

Example two

On the basis of the first embodiment, the second embodiment of the present application provides a method for preparing an octadecene suspension and a nanoporous anti-reflective film in an octadecene suspension layer of a four-terminal stacked perovskite solar cell based on a silicon quantum dot concentrator:

1. preparation of SiQD-LSC:

the SiQD-LSC main body framework is composed of a front quartz glass piece, a rear quartz glass piece and a PMMA ring in the middle. The thickness of the front and rear quartz glass sheets is 1mm, and the thickness of the PMMA ring is 2 mm. The cavity consisting of quartz glass and PMMA ring is filled with SiQD colloid. The surface of the quartz glass on the front side is plated with PMMA nano porous ARC. The synthesis of siqds is based on a developed top-down fabrication process comprising the steps of:

step 1, performing electrochemical etching on a silicon wafer in an electrolyte mixture containing HF and methanol under the condition of constant current, wherein the silicon wafer can be reused until the silicon wafer is penetrated by the electrochemical etching;

step 2, immediately immersing the silicon wafer into the deoxidized pure 1-octene after the electrochemical etching is finished, and carrying out white light induced hydrosilylation reaction under white light; the deoxygenated pure 1-octene is in a chamber filled with nitrogen;

step 3, collecting the photoluminescent porous silicon layer and the 1-octene on the surface of the silicon wafer, and transferring the photoluminescent porous silicon layer and the 1-octene into a grinding tank for high-energy ball milling to obtain turbid suspension;

and 4, centrifuging the turbid suspension obtained in the step 3, collecting yellow semitransparent supernatant, and completely evaporating 1-octene by using a rotary evaporator to obtain dry solid powder of silicon quantum dot nanoparticles (SiQDNPs) passivated with 1-octene.

The silicon wafer in the step 1 is a p-type crystal silicon wafer.

And the grinding tank in the step 3 is a zirconium oxide grinding tank.

The yellow translucent supernatant in step 4 contains 1-octene passivated silicon quantum dot nanoparticles (SiQDNPs).

The constant current in the step 1 is 0.1mA cm^-1To 10mA cm^-1(ii) a The concentration of HF ranges from 1 wt% to 49 wt%, and the volume ratio of HF to methanol ranges from 1:10 to 10: 1.

The time length of the electrochemical etching in the step 1 is 1min to 10 hr; the duration of the hydrosilylation reaction in the step 2 is 1hr to 100 hr; the time period of the high-energy ball milling in the step 3 is 1-100 hr.

The rotation speed of the centrifugation in the step 4 is 100rcf to 20000rcf, and the centrifugation time is 10sec to 1 hr.

The evaporation time of the rotary evaporator in the step 4 is 1min to 1hr, and the evaporation temperature is 30 ℃ to 100 ℃.

As shown in FIG. 2, SiQDs can form uniform and stable suspensions in various nonpolar organic solvents, such as toluene, n-hexane, and 1-Octadecene (ODE), and SiQDs in the suspensions in the ODE mainly absorb ultraviolet rays and have weak absorption in a visible light band of 400nm to 500 nm. The SiQD suspension appears pale yellow under white light due to slight blue light absorption. Under 365nm monochromatic light excitation, the SiQD suspension emits bright red fluorescence, the peak wavelength of the SiQD suspension is 690nm, and the photoluminescence quantum efficiency (PLQY) is 38.86%. Further, the PL peak wavelength remained almost unchanged when the excitation wavelength was changed to 465nm and 525 nm. Most importantly, the Stokes shift between the absorption and emission peaks is large, which is beneficial for suppressing the reabsorption effect of SiQD fluorescence. As shown in fig. 3, A, B is the transmission spectra of pure LSC and SiQD-LSC with different concentrations of SiQD; c is the absorption spectra of SiQD-LSC (solid line) and SiQD (dashed line) containing different concentrations of SiQD; d is the part of solar ultraviolet rays, namely the part of 300nm to 400nm in the AM1.5G solar spectrum, and the ratio of SiQD-LSC of SiQD with different concentrations is determined; the internal inset shows SiQD-LSC (SiQD concentration 1.08mg mL)^-1) Photograph under 365nm ultraviolet irradiation.

2. PMMA nanoporous ARC was prepared by a microphase separation method:

first, PMMA (Mw 15 kgmol)^-1) And polystyrene (PS, Mw ═ 14 kgmol)^-1) According to the following steps of 4: 6 was uniformly dissolved in chloroform to give a 1 wt% solution. The solution was then spin coated onto quartz plates cleaned with piranha solution. Subsequently, the quartz plate coated with the PMMA/PS coating is placed in a vacuum oven at 50 ℃ for 10h, then is annealed in an oven at 110 ℃ for 10min, and then is soaked in cyclohexane for 5min, so that the PS component is dissolved by the cyclohexane, and only the PMMA nano film is left on the substrate. Finally, after rinsing with deionized water for 10-60sec, followed by drying with nitrogen for 10-60sec, the SiQD-LSC can be constructed from quartz plates with PMMA nanoporous ARC. The PMMA film has larger pores at the top and smaller pores at the bottom, producing an effective refractive index between 1.2 and 1.3 at 300nm to 800 nm. The reflectance of the quartz plate with PMMA nanoporous ARC was significantly reduced compared to the single quartz plate, from 7.64% to 6.97%, 7.15% to 4.33%, 7.07% to 4.68% at 400nm, 600nm and 800nm, respectively (fig. 2B).

Optical properties of SiQD-LSC devices:

the utility model discloses the transmission spectrum to the SiQD-LSC that is filled with different concentration SiQD suspensions has been characterized (fig. 3A and 3B). The addition of only ARC (line B) increased the transmission by an average of 3% in the 400nm to 800nm band compared to a single LSC without SiQD and PMMA nanoporous ARC (line a). When the SiQD concentration increased to 0.13mg mL^-1(line C) and 0.27mg mL^-1(line D), the transmission in the ultraviolet to blue wavelength range drops significantly, while the transmission in the green to near infrared wavelength range remains higher than for pure LSC. When the SiQD concentration was further increased to 0.54mg mL^-1(line E), 1.08mg mL^-1(line F), 2.16mg mL^-1(line G) and 4.32mg mL^-1(line H) the transmission is lower for almost all wavelengths than for pure LSC. Although the increase in transmittance is reduced by absorption of the siqds (particularly at high concentrations), the absorbed incident light is converted to red fluorescence and absorbed by the rear PSC and the side silicon photovoltaic sheets to generate power.

Is filled withThe absorption spectra of SiQD-LSC at different concentrations (solid line in FIG. 3C) are obtained by subtracting the corresponding transmission spectrum (FIG. 3A) and reflection spectrum data (FIG. 2B) from 1, while the absorption spectra of SiQDs at different concentrations (dashed line in FIG. 3C) can be obtained by subtracting the transmission spectra of SiQD-LSC at other concentrations from the transmission spectrum of SiQD-LSC at zero concentration (solid line B in FIG. 3A). As shown in FIG. 3C, the absorption spectra of SiQD-LSC and SiQDs are substantially identical at wavelengths above 400nm, indicating that the absorption of the ARC, the two quartz plates and the ODE in the visible to near infrared wavelength range (solid line B in FIG. 3C) is negligible. Finally, to understand the ability of SiQD-LSC to remove ultraviolet light that may cause PSC instability, we calculated the proportion of UV passing through SiQD-LSC in the solar spectrum at am1.5g intensity (300nm to 400 nm). As the concentration of SiQD increased from 0 to 0.54 to 4.32mg mL^-1The proportion of uv light passing through SiQD-LSC dropped from 90% to 44% to 3%. This indicates that solar ultraviolet rays absorbed by SiQDs are converted into red fluorescence. Most of the red fluorescence propagates to the four edges of the SiQD-LSC, except for escape cone losses at the front and back surfaces of the SiQD-LSC.

In this example, a silicon photovoltaic sheet is used to absorb the SiQD fluorescence propagating in the lateral direction, while the PSC primarily absorbs the remaining solar radiation passing through the SiQD-LSC. PSC consists of 5 sub-photovoltaic units connected in series, each sub-unit having FTO/TiO₂/ZrO₂Perovskite ((5-AVA)_xMA_1-xPbI₃) A carbon device structure. It should be noted that, in order to avoid the complexity of the wiring, only one silicon photovoltaic cell is attached to the edge of the SiQD-LSC in the following experiment, and the total amount of electricity generated by the SiQD-LSC is equal to the amount of electricity generated by the silicon photovoltaic cell multiplied by 4. In addition, in the measurement process, the light absorption area is always 4cm × 4cm, and the light source is completely shielded by the parts except the light absorption area.

EXAMPLE III

On the basis of the first embodiment and the second embodiment, the third embodiment of the present application provides the effects and effects of the four-terminal stacked perovskite solar cell based on the silicon quantum dot concentrator when a 1mm air gap exists between the SiQD-LSC and the PSC:

when a 1mm air gap exists between SiQD-LSC and PSC, under 365, 465 and 525nm LED illumination, characterization is madeExternal Quantum Efficiency (EQE) of SiQD-LSC and post PSC. As the concentration of SiQD increased from 0 to 4.32mg mL^-1The EQE of SiQD-LSC increases at 365nm well over 465nm and 525nm, but reaches 1.08mg mL^-1The peak is reached (fig. 5A). This is due to the near saturation of siqds for uv absorption (fig. 3C), and the effect on light secondary absorption at high SiQD concentrations. In contrast, only a portion of the incident light reaches the PSC through SiQD-LSCs, so the EQE of the PSC decreases as the concentration of siqds increases (fig. 5B). Most importantly, when the concentration of SiQD is higher than 0.27mg mL^-1At 365nm, the overall EQE of the SiQD-LSC/PSC tandem solar cell is higher than the EQE of a single PSC at 365 nm. The EQE peak appeared at 1.08mg mL^-1At 15.36%, a 47% improvement was achieved compared to the single PSC under the same conditions (fig. 5C). On the other hand, except in 2.16mg mL^-1And 4.32mg mL^-1In addition, EQE under 465nm and 525nm LED illumination was lower than single PSC.

Except that to the analysis based on the EQE numerical value that the short-circuit current measurement reachd under monochromatic light, under xenon lamp illumination, the utility model discloses the PCE to top SiQD-LSC device, rear PSC device and both holistic has carried out the sign. As the concentration of SiQD increased from 0 to 4.32mg mL^-1The PCE of SiQD-LSC increases linearly, increasing from 0 to 0.13% (fig. 5D), while the PCE of PSC decreases monotonically, decreasing from 2.20% to 1.70% (fig. 5E). Furthermore, the overall PCE of SiQD-LSC/PSC tandem solar cells is lower than a single PSC at all SiQD concentrations (fig. 5F). In summary, SiQD-LSC/PSC tandem solar cells achieve higher EQE at high SiQD concentrations but lower PCEs at all SiQD concentrations than single PSC. This result is attributed to the series connection of five subunits of the PSC, which is disadvantageous for extracting photoexcited carriers under short circuit conditions. In contrast, the short-circuit current of the SiQD-LSC is calculated by multiplying the short-circuit current of the silicon photovoltaic cell by 4, i.e. four silicon photovoltaic cells are connected in parallel. Thus, the increase in EQE caused by SiQD-LSC (fig. 5A) may overcome the decrease in EQE brought about by PSC (fig. 5B), particularly under 365nm light illumination. However, in evaluating the PCE, both the short circuit current and the open circuit voltage need to be considered. Consider that the open circuit voltage of a PSC with five subunits connected in series is much greater than that of a SiQD-LSC (Table)1) The PCE drop caused by PSC (FIG. 5E) exceeds the PCE rise caused by SiQD-LSC (FIG. 5D).

Table 1 shows xenon lamp irradiation (8.109mW cm)^-2) When the SiQD concentration is different, the values of the short circuit current (Isc), the open circuit voltage (Voc), and the Fill Factor (FF) of the SiQD-LSC and the rear PSC are different. Note that the Isc values for SiQD-LSCs shown in the table are equal to the Isc value for a single silicon photovoltaic sheet multiplied by 4.

TABLE 1 parameter tables for SiQD-LSC, short-circuit current (Isc), open-circuit voltage (Voc) and Fill Factor (FF) of SiQD-LSC, rear PSC under xenon lamp irradiation at different SiQD concentrations

Optical efficiency (. eta.) of SiQD-LSC_opt) Is defined as: the proportion of the emitted SiQD fluorescence that is received by the silicon photovoltaic cell and can be calculated by the following equation:

wherein Δ I_sc(at 1.08mg mL^-1Lower 2.85X 10^-4A) Represents the short-circuit current, q (1.6x 10), generated in the silicon photovoltaic cell after subtraction of the value at zero concentration^-19C) Representing the amount of charge per unit of charge,

(about 0.9) represents the quantum efficiency of a silicon photovoltaic sheet under 690nm light irradiation, I_light(2.214mW cm^-2) Representing the intensity of 365nm monochromatic light, A_SiQD(at 1.08mg mL^-161.71% at concentration) represents the absorbance of SiQD at 365nm monochromatic light, hv_365nm(5.44x10^-19J) Is the photon energy of a 365nm photon,

(38.86%, measured) represents PLQY at 365nm for the SiQD suspension. When the concentration of SiQD is 1.08mg mL^-1Eta of SiQD-LSC_optAbout 50.66%, similar to the previously prepared SiQD-LSC. According to Snell's law, in the absence of SiQDTime, theoretical eta_optHas a maximum value of (1-n)_air ²/n_ODE ²)^1/272% where n_air＝1,n_ODE1.44. The optical losses therein can be attributed to re-absorption by the siqds and absorption and scattering by the non-ideal waveguide structure.

Example four

Based on the first to third embodiments, the fourth embodiment of the present application provides the effects and effects of the four-terminal stacked perovskite solar cell based on the silicon quantum dot concentrator when there is no air gap between the SiQD-LSC and the PSC:

when the air gap is eliminated and a mirror oil (refractive index 1.52) is added between the SiQD-LSC and the PSC, the SiQD-LSC is no longer completely surrounded by air and therefore η of the SiQD-LSC_optFrom 50.66% down to 12.73%. This indicates that SiQD fluorescence photons, in addition to front surface escape cone losses, tend to propagate to the rear PSC rather than the lateral silicon photovoltaic plate. In this case, the SiQD-LSC acts more like a luminescence down-conversion device than a luminescence concentrator. Thus, the EQE and PCE of air-gapless SiQD-LSCs (fig. 6A and 6D) are much smaller than those of air-gapped SiQD-LSCs (fig. 5A and 5D). For example, under 365nm light irradiation, at a SiQD concentration of 1.08mg mL^-1While, the EQE of SiQD-LSC decreased from 10.94% to 2.75%; at 4.32mg mL^-1At concentration, the PCE of SiQD-LSC dropped from 0.13% to 0.02%. On the other hand, the EQE and PCE of PSC without air gaps (FIGS. 6B and 6E) are slightly improved over PSC with air gaps (FIGS. 5B and 5E). Most importantly, the SiQD concentration was 0 to 1.08mg mL^-1In the range, the EQE of the SiQD-LSC/PSC laminated solar cell is respectively improved by 4.6 percent and 5.0 percent compared with that of a single PSC cell under the irradiation of 465nm and 525nm light rays. And the PCE is improved by 6.2% maximally over a single PSC cell. The situation (fig. 6C and 6F, table 3) is very different, in the presence of air gaps, at higher concentrations of siqds, the total EQE of the stacked cell is higher than a single PSC, while its total PCE is always lower than a single PSC (fig. 5C and 5F, table 3). It can be seen that the air gap, although providing guided wave capability to the SiQD-LSC, introduces a reflective interface at the PSC front surface, which counteracts the transmission of PMMA nanoporous ARC at the SiQD-LSC front surfaceThe refractive index is enhanced. Finally, when the concentration of SiQD is 1.08mg mL^-1In this case, although the PCE achieved by the SiQD-LSC/PSC stacked solar cell is substantially identical to that of a single PSC (fig. 6F), the SiQD-LSC in the upper half of the stack structure absorbs 69% of the solar uv rays (fig. 3D), making the PSC in the lower half of the stacked cell more stable.

TABLE 2 parameter tables for SiQD-LSC, short-circuit current (Isc), open-circuit voltage (Voc) and Fill Factor (FF) for different SiQD concentrations under xenon lamp irradiation

TABLE 3 table of values that SiQD-LSC/PSC tandem solar cells can achieve for efficiency (PCE) and EQE at different concentrations of SiQD

EQE of SiQD-LSC/PSC tandem solar cells at different concentrations of SiQD under 365nm, 465nm, 525nm monochromatic light irradiation, and PCE thereof under xenon lamps. The highlighted values represent enhancement compared to a single PSC value.

And (4) conclusion:

the utility model provides a four-terminal lamination solar cell, this solar cell contain one kind and fill have siQDs and put the LSC in PSC the place ahead. The front surface of the SiQD-LSC was uniformly covered with PMMA nanoporous ARC, increasing the transmission by 3% from visible to near infrared. Siqds suspended in ODE within the LSC absorb mainly the UV part of the solar radiation and emit red fluorescence with a peak wavelength of 690nm, with a PLQY of 38.86% under 365nm light. The fluorescence emitted by the siqds propagates through the planar waveguide structure to the LSC structure edge where the concentrated fluorescence is converted into electrical energy by a conventional silicon photovoltaic chip. After passing through the front UV absorbing SiQD-LSCs, the rest of the incident sunlight is absorbed by the rear PSCs. When there are air gaps between the SiQD-LSC and PSC, at high SiQD concentrations, SiQD-LSC/PSC tandem solar cells can be at 365nm compared to a single PSCHigher EQE was obtained under illumination at 465nm and 525 nm. In particular, when the concentration is 1.08mg mL^-1The peak EQE under 365nm irradiation was 15.36%, which is a 47% increase over single PSC. However, the PCE of a SiQD-LSC/PSC tandem solar cell is lower than a single PSC at all concentrations of siqds. Conversely, the optical efficiency of the SiQD-LSC decreased from 50.66% to 12.73% after the air gap was removed, indicating that the fluorescence photons emitted by the siqds, in addition to the front surface escape cone loss, tend to propagate more to the rear PSC than to the side silicon photovoltaic sheets. In this case, the SiQD-LSC becomes a luminescent down-converter rather than a luminescent concentrator, and SiQD-LSC/PSC tandem solar cells achieve up to 4.6% and 5.0% EQE enhancement at low SiQD concentrations and up to 6.2% PCE enhancement under xenon lamps, respectively, than a single PSC under 465nm and 525nm monochromatic light illumination. In particular, at 1.08mg mL^-1In time, although the PCE of the tandem solar cell is substantially the same as the single PSC, the SiQD-LSC of the upper layer absorbs 69% of the solar uv rays, making the PSC of the lower layer more stable than the single PSC structure.

Under the condition that an air gap is reserved between the SiQD-LSC and the perovskite solar cell, the SiQD colloid arranged in the interlayer of the two quartz plates absorbs the ultraviolet part in the solar spectrum and emits red light at the same time. The red light then passes along the waveguide structure to the side edge of the quartz plate, and is finally absorbed by the side silicon solar cell plate to generate electricity. The remaining incident sunlight will be absorbed by the following PSCs to generate electrical energy. The sum of External Quantum Efficiencies (EQE) of SiQD-LSC and PSC devices was significantly improved under 365nm monochromatic light compared to a single homogeneous PSC device.

When the air gap between the SiQD-LSC and the PSC is removed, the optical medium surrounding the SiQD-LSC is no longer just air, and thus the waveguide effect of the SiQD-LSC is drastically reduced. In this case, the SiQD-LSC acts as a luminescent down converter, and most of the light originally absorbed by the LSC-side edge silicon solar cells is absorbed by the rear PSC. In this state, SiQD-LSC/PSC tandem solar cells enable significant improvements in efficiency (PCE) and uv stability compared to a single homogeneous PSC device.

Claims (6)

1. A four-terminal stacked perovskite solar cell based on a silicon quantum dot concentrator, comprising: a silicon quantum dot concentrator (10) and a perovskite solar cell (105); the perovskite solar cell (105) is arranged below the silicon quantum dot concentrator (10);

the silicon quantum dot concentrator (10) consists of a nano porous antireflection film (101), a front quartz plate (102), a PMMA ring (103) and a rear quartz plate (104); the upper surface of the front quartz plate (102) is uniformly attached with a nano-porous antireflection film (101); wherein an octadecylene suspension layer (106) is formed among the front quartz plate (102), the PMMA ring (103) and the rear quartz plate (104); silicon cell pieces (107) are adhered to the peripheral edges of the silicon quantum dot concentrator (10);

the silicon cell (107) and the perovskite solar cell (105) are electrically connected.

2. The silicon quantum dot concentrator based four-terminal stacked perovskite solar cell of claim 1, wherein: when an air gap is arranged between the perovskite solar cell (105) and the silicon quantum dot concentrator (10), the width of the air gap is 0.2-2 mm; when no air gap is arranged between the perovskite solar cell (105) and the silicon quantum dot concentrator (10), the original air gap position is filled with filling materials.

3. The silicon quantum dot concentrator based four-terminal stacked perovskite solar cell of claim 2, wherein: the filling material is mirror oil.

4. The silicon quantum dot concentrator based four-terminal stacked perovskite solar cell of claim 1, wherein: the perovskite solar cell (105) is formed by connecting a plurality of sub-cells in series, and the sub-cells are made of perovskite type metal halide semiconductors; and the perovskite solar cell (105) is sealed between two pieces of glass by butyl rubber, and the thickness of the packaging glass is 2.2-3.2 mm.

5. The silicon quantum dot concentrator based four-terminal stacked perovskite solar cell of claim 1, wherein: the silicon quantum dot concentrator (10) is adhered with a silicon cell (107) at the peripheral edge by epoxy resin; the silicon cell (107) and the perovskite solar cell (105) are electrically connected in parallel.

6. The silicon quantum dot concentrator based four-terminal stacked perovskite solar cell of claim 1, wherein: the nano porous antireflection film (101) is made of polymethyl methacrylate; the octadecene suspension layer (106) layer is filled with a suspension of octadecene; the thickness of the front quartz plate (102) is 0.1-10 mm, the thickness of the PMMA ring (103) is 0.1-10 mm, and the thickness of the rear quartz plate (104) is 0.1-10 mm.

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