Presentation Details
| Effects of Electron Irradiation and High-Intensity Laser Illumination on the Performance of InGaAsP Laser-Power Converters Sho Aonuki1, Yudai Yamashita2, Takaya Oshimo3, Kotona Tabata3, Takeru Yamada3, Masato Suzuki1, Natsuha Ochiai1, Yukiko Suzuki1, Kazuto Kashiwakura1, Yuka Oshima1, Kouichi Akahane4, Masakazu Arai3, Yohei Toriumi1, Madoka Takahashi1. 1Space Environment and Energy Laboratories, NTT, Inc., Musashino, Tokyo, Japan.2Basic Research Laboratories, NTT, Inc., Atsugi, Kanagawa, Japan.3University of Miyazaki, Miyazaki, Miyazaki, Japan.4National Institute of Information and Communications Technology, Koganei, Tokyo, Japan |
Abstract
The degradation behavior of laser-power converters (LPCs) under particle irradiation must be well understood for the application of optical wireless power-transmission (OWPT) systems in space. In this study, single-junction InGaAsP LPCs designed for 1064 nm lasers are exposed to 1 MeV electrons at fluences from 1 × 1014 to 1 × 1016 cm−2, and their current density–voltage characteristics are evaluated under two laser intensities (6.75 and 0.1 W·cm−2) and AM1.5G illumination. Before electron irradiation, the conversion efficiencies (η) reached 40.0% and 21.3% under 1064-nm-laser illumination at 6.75 and 0.1 W·cm−2, respectively, whereas η under AM1.5G was limited to 7.05% owing to parasitic absorption in the thick InP electron-transport layer. Electron irradiation primarily degraded the external quantum efficiency (EQE) at longer wavelengths, suggesting carrier-lifetime reduction. The short-circuit current density (JSC) under 1064-nm- laser illumination decreased more than that under AM1.5G illumination owing to the EQE reduction from 0.823 to 0.510 at 1065 nm. Under 6.75 W·cm−2 laser illumination, the remaining factor of the JSC improved to 0.637 compared to that under 0.1 W·cm−2 laser illumination (0.532), indicating that high-injection effects mitigated defect-related recombination. The η values after 1 × 1015 cm−2 electron irradiation were 57.4% and 47.7% of the initial value under 6.75 and 0.1 W·cm−2 illumination, respectively. These results demonstrate that operation under high-intensity laser illumination suppresses radiation-induced performance losses in InGaAsP LPCs, providing important insight for OWPT systems for space usage.
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.
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.