Proton irradiation of CdTe thin film photovoltaics deposited on cerium‐doped space glass

Abstract

Space photovoltaics is dominated by multi-junction (III-V) technology. However, emerging applications will require solar arrays with high specific power (kW/kg), flexibility in stowage and deployment, and a significantly lower cost than the current III-V technology offers. This research demonstrates direct deposition of thin film CdTe onto the radiation-hard cover glass that is normally laminated to any solar cell deployed in space. Four CdTe samples, with 9 defined contact device areas of 0.25 cm 2 , were irradiated with protons of 0.5-MeV energy and varying fluences. However, there are emerging applications which will require solar arrays with high specific power (kW/kg), flexibility in stowage and deployment, and a significantly lower cost than is currently available. 4New space PV technologies need to be developed to meet the needs of future advances in space exploration and energy harvesting. Some --------------------------------------------------------------------------------------------------------------------------------This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Proton Irradiation on Cesium‐Fluoride‐Free and Cesium‐Fluoride‐Treated Cu(In,Ga)Se2 Solar Cells and Annealing Effects under Illumination

“…As can be seen in Figure S1, Supporting Information, the degradation of EQE curves at longer wavelengths is correlated with the increasing proton fluence, whereas the EQE curves increased in the shorter wavelength region (especially) around 520 nm (for 3 × 10 12 , 1 × 10 13 , and 2 × 10 13 cm −2 ). It can be explained by increased absorption profile around buffer/CIGS interfacial owing to the buried junction characteristic, pushing the junction toward Mo side …”

“…Recently, chalcopyrite Cu(In,Ga)S,Se 2 (CIGSSe) thin‐film solar cells with air mass (AM) 1.5 conversion efficiency exceeded 23%, the highest value among the thin‐film solar cell technologies . These highest power conversion efficiency and high radiation tolerance show good potential for space application . Flight data demonstrate no degradation of Cu(In,Ga)Se 2 (CIGS) solar cell performance by proton irradiation and thermal annealing .…”

“…[2] These highest power conversion efficiency and high radiation tolerance show good potential for space application. [3][4][5][6][7][8][9][10][11][12][13][14][15] Flight data demonstrate no degradation of Cu(In,Ga)Se 2 (CIGS) solar cell performance by proton irradiation and thermal annealing. [8] Kawakita et al suggested that CIGS thin-film solar cells do not degrade in space by proton from an application point of view owing to the moderate temperature (50 C) of solar paddles in geostationary orbit and minority carrier injection during regular operation.…”

“…It can be explained by increased absorption profile around buffer/CIGS interfacial owing to the buried junction characteristic, pushing the junction toward Mo side. [6] Figure 4 shows the space charge region (SCR) and net carrier concentration (N CV ) determined from C-V measurements at V ¼ 0 V for (Figure 4a Figure 5a,b represents the typical N CV profiles of CsF-free CIGS solar cells before and after proton irradiation at fluences of 3 Â 10 12 cm À2 (Region I) and 5 Â 10 14 cm À2 (Region II), respectively. From these figures, the following conclusion can be drawn: 1) N CV decreased after proton irradiation.…”

Degradation Under Influence of Radiation Defects of Detector Properties of CdTe and Cd0.9Zn0.1Te Irradiated by Neutrons

“…Along with Cd0.9Zn0.1Te, CdTe is often considered as a detector material. During operation, the detectors are exposed to ionizing radiation, the effect of which on the crystals is the subject of research, for example, irradiation with protons [5], electrons [6], gamma rays [7], and neutrons [8] which have increased penetrating power. As a result of neutron bombardment, the radiation defects arise in a semiconductor crystal, which correspond to energy levels in the band gap, acting as centers of capture and recombination of nonequilibrium charge carriers generated by the detected radiation.…”