[15p-W2_402-1~12] 15.5 IV族結晶，IV-IV族混晶

14:00 〜 14:15英語発表

[15p-W2_402-3] Ge_0.8Sn_0.2/n-Ge Heterostructure Grown by Sputtering for Mid-Wave Infrared Photodetectors

〇Rahmat Hadi Saputro¹, Tomo Tanaka², Hiroyuki Ishii¹, Kousaku Goto³, Shigehisa Shibayama³, Masashi Kurosawa³, Osamu Nakatsuka³, Tatsuro Maeda¹ (1.AIST, 2.NEC Corp., 3.Nagoya Univ.)

キーワード：

GeSn、Sputtering、Photodetector

We report the fabrication of mid-wave infrared (MWIR) photodetectors based on Ge_0.8Sn_0.2/n-Ge heterostructures grown by sputtering, achieving high Sn composition (~20%) and an almost fully strain-relaxed epitaxial layer. The sputtering process enabled deposition rates faster than 10 nm/min, supporting scalable production of thick Ge_1-xSn_x films. The device exhibited diode behavior with an on-off ratio >10³, low dark current (0.03 A/cm² at -1 V), and a multi-band optical response extending to 2.8 μm. Detectivity reached 3.9×10⁹ cm·Hz^1/2·W^-1 at 300 K for n-Ge and 2.8×10⁸ cm·Hz^1/2·W^-1 for Ge_0.8Sn_0.2 at 240 K, demonstrating sputtering as a high-throughput approach for MWIR sensing and imaging applications.