CN201397817Y - Multi-junction gallium arsenide solar battery - Google Patents

Abstract

The utility model relates to a multi-junction gallium arsenide solar battery, which comprises a top battery which is mainly formed by GaInP, a middle battery which is mainly formed by InGaAs and a bottom battery which is mainly formed by Ge, wherein AlInP(p<+>)/AlGaAs(p<++>)-GaInP(n<++>)/AlInP(n<+>) or AlGaInP(p<+>/AlGaAs(p<++>)-GaInP(n<++>)/AlInP(n<+>) tunneling junction connection structure is arranged between the top and the middle batteries. By adopting the above tunneling junction connection structure, the multi-junction gallium arsenide solar battery not only can obviously reduce the reflection of incoming rays and improve the current density of the battery, but also can improve the transforming efficiency of the three-junction battery.

Description

Multijunction gallium arsenide solar cell

Technical field

The utility model relates to solar cell, particularly a kind of multijunction gallium arsenide solar cell.

Background technology

GaInP/InGaAs/Ge three-junction solar battery efficient surpasses 40%, is present most effective solar cell, becomes one of focus for people's research.We find in the process of development GaInP/InGaAs/Ge three-junction solar battery, there is stronger standing wave reflection in absorption bands at middle battery InGaAs, reduced the current density of middle battery, there is this problem equally in import GaInP/InGaAs/Ge three-junction solar battery.

The structure of the typical three-junction solar battery of prior art is: the top battery is AlInP (n ⁺, 35nm)/GaInP (n/p, 520nm)/AlInP (p ⁺, 40nm); Middle battery is AlInP (n ⁺, 50nm)/InGaAs (n/p, 3.5 μ m)/AlGaAs (p ⁺, 100nm); End battery is GaInP (n ⁺, 100nm)/Ge (n ⁺, 100nm)/Ge (p ⁺, 170 μ m); Tunnelling is become AlGaAs (p ⁺⁺)-GaInP (n ⁺⁺) and GaAs (p ⁺⁺)-GaAs (n ⁺⁺).In order to reduce reflection of incident light, further improve the efficient of GaInP/InGaAs/Ge three-junction solar battery, we have analyzed the reason that produces this phenomenon: the GaInP/InGaAs/Ge three-junction solar battery adopts three sub-batteries to absorb the incident light of different-energy respectively, adopts tunnel junctions (AlGaAs (p between the sub-battery ⁺⁺)-GaInP (n ⁺⁺) and GaAs (p ⁺⁺)-GaAs (n ⁺⁺) connect, relate to GaInP, InGaAs, AlInP, AlGaAs, materials such as Al (Ga) InP, GaAs, because the refractive index difference of these materials, cause in battery, producing standing wave effect, especially between the uptake zone of middle battery, produce strong standing wave, increased the reflection of this wave band, reduced sunlight and entered battery, thereby the generation electric current of battery reduces in making, and the efficient of GaInP/InGaAs/Ge three-junction solar battery is reduced.

The utility model content

The purpose of this utility model is to provide a kind of multijunction gallium arsenide solar cell that can slacken the standing wave effect in the multijunction gallium arsenide solar cell.

To achieve these goals, the utility model has adopted following technical scheme: a kind of multijunction gallium arsenide solar cell, comprise the top battery that mainly constitutes, the middle battery and the main end battery that constitutes by Ge that mainly constitute by InGaAs by GaInP, between top battery and middle battery and middle battery and end battery, be respectively equipped with the tunnel junctions syndeton, be characterized in:

Tunnel junctions syndeton between described top battery and the middle battery comprises four layer materials, the AlInP that the ground floor material mixes for the p type, second layer material is the heavily doped AlGaAs of p type, trilaminate material is the heavily doped GaInP of n type, the AlInP that the 4th layer material mixes for the n type, wherein the AlInP of p type doping is the back of the body field of top battery, and thickness is 100nm～150nm; The AlInP that the n type mixes is the back of the body field of middle battery, and thickness is 100nm～150nm; The thickness of the heavily doped AlGaAs of p type is 10nm～15nm; The thickness of the heavily doped GaInP of n type is 10nm～15nm.

Tunnel junctions syndeton between described top battery and the middle battery comprises four layer materials, the AlGaInP that the ground floor material mixes for the p type, second layer material is the heavily doped AlGaAs of p type, trilaminate material is the heavily doped GaInP of n type, the AlInP that the 4th layer material mixes for the n type, wherein the AlInP of p type doping is the back of the body field of top battery, and thickness is 100nm～150nm; The AlInP that the n type mixes is the back of the body field of middle battery, and thickness is 100nm～150nm; The thickness of the heavily doped AlGaAs of p type is 10nm～15nm; The thickness of the heavily doped GaInP of n type is 10nm～15nm.

Multijunction gallium arsenide solar cell of the present utility model not only can significantly reduce reflection of incident light owing to adopted above tunnel junctions syndeton between top battery and middle battery, and the current density of battery in the improvement can also improve the conversion efficiency of three junction batteries.The short circuit current that improves battery in the back has increased 0.65mA/cm ²Efficient is 27.1% before improving, and improves behind efficiency and brings up to 27.8%.

Description of drawings

Fig. 1 is the structural principle schematic diagram of multijunction gallium arsenide solar cell of the present utility model;

Fig. 2 is the structural principle schematic diagram of the tunnel junctions syndeton in the utility model.

Fig. 3 is for adopting reflecting spectrograph CRAY5000 to test the test result comparison diagram that obtains respectively to multijunction gallium arsenide solar cell of the present utility model and prior art battery.

Embodiment

Referring to Fig. 1, Fig. 2, multijunction gallium arsenide solar cell of the present utility model, comprise (n+ by AlInP, 35nm)/GaInP (n/p, 520nm)/AlInP (p+, 120nm) the top battery 1 of Gou Chenging, by AlInP (n+, 120nm)/InGaAs (n/p, 3.5 μ m)/AlGaAs (p+, 100nm) the middle battery 2 of Gou Chenging and by GaInP (n ⁺, 100nm)/Ge (n ⁺, 100nm)/Ge (p ⁺, 170 μ m) and the end battery 3 that constitutes, between top battery and middle battery, be provided with (p by AlInP ⁺)/AlGaAs (p ⁺⁺)-GaInP (n ⁺⁺)/AlInP (n ⁺) or AlGaInP (p ⁺)/AlGaAs (p ⁺⁺)-GaInP (n ⁺⁺)/AlInP (n ⁺) the tunnel junctions syndeton 4 that constitutes.Wherein 41 represent AlInP (p ⁺) or AlGaInP (p ⁺), being the back of the body field of top battery, thickness is 100nm～150nm; 44 expression AlInP (n ⁺), being the back of the body field of middle battery, thickness is 100nm～150nm; 42 expression AlGaAs (p ⁺⁺), thickness is 10nm～15nm; 43 expression GaInP (n ⁺⁺), thickness is 10nm～15nm.(p ⁺) doping of expression p type, (n ⁺) doping of expression n type, (p ⁺⁺) expression p ⁺⁺Heavy doping, (n ⁺⁺) expression n ⁺⁺Heavy doping.Be provided with tunnel junctions syndeton 5 between middle battery and end battery, this tunnel junctions syndeton 5 is same as the prior art, does not do concrete statement.

For further specifying concrete technology contents of the present utility model, the utility model is further described below in conjunction with embodiment.

Adopt low pressure metal organic chemical vapor deposition (MOVPE) equipment (the Model Aixtron 200-4) GaInP/InGaAs/Ge three that on p type Ge substrate, grow to tie stacked solar cell, cascade solar cells.The III clan source is respectively TMGa, TMAl, TMIn; Group V source is respectively SiH ₄And PH ₃P type dopant is SiH ₄N type dopant is DEZn and CCl ₄Carrier gas is H ₂, the online purifying of palladium filter.

Battery structure of the present utility model: the top battery be AlInP (n+, 35nm)/GaInP (n/p, 520nm)/AlInP (p+, 120nm); In battery be AlInP (n+, 120nm)/InGaAs (n/p, 3.5 μ m)/AlGaAs (p+, 100nm); End battery be GaInP (n+, 100nm)/Ge (n+, 100nm)/Ge (p+, 170 μ m); Tunnel junctions syndeton between top battery and the middle battery is AlInP (p ⁺)/AlGaAs (p ⁺⁺)-GaInP (n ⁺⁺)/AlInP (n ⁺) or AlGaInP (p ⁺)/AlGaAs (p ⁺⁺)-GaInP (n ⁺⁺)/AlInP (n ⁺).

Main back growing technology comprises: photoetching, evaporation, selective corrosion, thermal annealing etc.Backplate is PdAg, and front electrode is AuGeNi/Au.Double layer antireflection coating TiO2/SiO ₂Adopt Spectrolab x-25 simulator as the AM0 light source, measure the photovoltaic performance of battery sample.Adopt the GaInP of Spectrolab ₂/ GaAs laminated cell sample is demarcated light source (135.3mW/cm as the reference battery ²).Adopt the reflectance spectrum of reflecting spectrograph CRAY5000 test battery.

Fig. 3 adopts reflecting spectrograph CRAY5000 to test the test result comparison diagram that obtains respectively to multijunction gallium arsenide solar cell of the present utility model and prior art battery.Solid line is depicted as the reflectivity of multijunction gallium arsenide solar cell of the present utility model to different wave length among the figure, and astragal is depicted as the reflectivity of prior art typical case multijunction gallium arsenide solar cell to different wave length.As seen from the figure, in the 650-850nm wave-length coverage, multijunction gallium arsenide solar cell of the present utility model roughly is stabilized in about 5% the reflectivity of different wave length, and littler than the reflectivity of prior art typical case multijunction gallium arsenide solar cell.

Claims (2)

1, a kind of multijunction gallium arsenide solar cell, comprise the top battery that mainly constitutes, the middle battery and the main end battery that constitutes by Ge that mainly constitute by InGaAs by GaInP, between top battery and middle battery and middle battery and end battery, be respectively equipped with the tunnel junctions syndeton, it is characterized in that:

Tunnel junctions syndeton between described top battery and the middle battery comprises four layer materials, the AlInP that the ground floor material mixes for the p type, second layer material is the heavily doped AlGaAs of p type, trilaminate material is the heavily doped GaInP of n type, the AlInP that the 4th layer material mixes for the n type, wherein the AlInP of p type doping is the back of the body field of top battery, and thickness is 100nm～150nm; The AlInP that the n type mixes is the back of the body field of middle battery, and thickness is 100nm～150nm; The thickness of the heavily doped AlGaAs of p type is 10nm～15nm; The thickness of the heavily doped GaInP of n type is 10nm～15nm.

2, a kind of multijunction gallium arsenide solar cell, comprise the top battery that mainly constitutes, the middle battery and the main end battery that constitutes by Ge that mainly constitute by InGaAs by GaInP, between top battery and middle battery and middle battery and end battery, be respectively equipped with the tunnel junctions syndeton, it is characterized in that:

Tunnel junctions syndeton between described top battery and the middle battery comprises four layer materials, the AlGaInP that the ground floor material mixes for the p type, second layer material is the heavily doped AlGaAs of p type, trilaminate material is the heavily doped GaInP of n type, the AlInP that the 4th layer material mixes for the n type, wherein the AlInP of p type doping is the back of the body field of top battery, and thickness is 100nm～150nm; The AlInP that the n type mixes is the back of the body field of middle battery, and thickness is 100nm～150nm; The thickness of the heavily doped AlGaAs of p type is 10nm～15nm; The thickness of the heavily doped GaInP of n type is 10nm～15nm.

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