Presentation Details
| Radiation Tolerance of Ultra-Thin InP Solar Cells for Space Applications (yes) Venkata S.A.Chaluvadi1, Stefan Diesing1, 2, Toluwalase Agoro1, Iwan Davies3, Louise C.Hirst1. 1University of Cambridge, Cambridge, United Kingdom.2University of Sheffield, Sheffield, United Kingdom.3IQE plc., Cardiff, United Kingdom |
Abstract
We demonstrate the high radiation tolerance of novel ultra-thin InP solar cells, highlighting their potential for long-lifetime high radiation environments and reductions in launch mass and respective cost through cover glass thinning. Ultra-thin solar cells have previously shown intrinsic radiation tolerance owing to short minority-carrier diffusion lengths for carrier collection. In this study, InP solar cells with absorber thicknesses of 100, 160, and 300 nm were characterized before and after 2 MeV proton irradiation up to fluences of 1 × 1016 p+ cm−2. While all cells exhibit similar degradation in Voc at higher fluences, thickness-dependent device performance is pronounced in short-circuit current. Thinner absorbers exhibit significantly delayed onset of Jsc degradation. The intrinsic advantage of InP is further shown at 1 × 1015 p+ cm−2 where the 160 nm InP device has a significantly higher remaining factor (0.81) than a comparable 80 nm GaAs device (0.30) despite twice the thickness. At the highest fluence investigated, equivalent to ~35 years in GEO or ~6 years in GNSS, the 100 nm InP device maintains a Jsc RF of 0.77, whereas thicker InP devices and a thinner GaAs device have collapsed. Preliminary results integrating a back surface reflector showcase a ~24-33% improvement in beginning-of-life Jsc. These results demonstrate the intrinsic radiation resilience of ultra-thin InP solar cells, even compared to ultra-thin GaAs, and their promise to unlock longer lifetimes and extreme radiation environments.
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No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.