[TuP3A] Epitaxy and process

[TuP3A-21] Demonstration of GaSbN-Based Thermoradiative Diodes Grown on GaP Substrates for Large-Area Scalability

〇Yamato Kyuno¹, Tetsuya Nakamura², Keito Sagane¹, Tensei Kawasaki¹, Hiroto Kawahara¹, Keisuke Yamane¹ (1. Toyohashi Tech. (Japan), 2. JAXA (Japan))

This paper reports on the development and performance analysis of GaSbN-based thermoradiative (TR) diodes on GaP substrates for space power applications. Theoretical modeling reveals that a slight reduction in bandgap (E_g) significantly enhances power density, highlighting the critical importance of bandgap engineering for TR devices. Since GaSb yields insufficient power under anticipated operating temperatures (~430 K), we utilized GaSbN for its E_g tunability. The device structure, p-GaSb:Mg/GaSbN/n-GaP, was designed to prevent substrate absorption and enable future large-area scalability via GaSb/GaP/Si heteroepitaxy. Experimental results from MBE-grown devices demonstrated a maximum power density of 13.6 μW/m² at T_c=413 K,T_a=73 K.