[20a-S321-1~10] 3.13 Semiconductor optical devices

▲ [20a-S321-1] Temperature dependence of dark current characteristics of InAs/GaSb type-II superlattice photodiode

〇Sundararajan Balasekaran¹, Kouhei Miura¹, Ken-ichi Machinaga¹, Daisuke Kimura¹, Takahiko Kawahara¹, Masaki Migita¹, Hiroshi Obi¹, Nitta Toshiyuki¹, Hiroshi Inada¹, Yasuhiro Iguchi¹, Tsukuru Katsuyama¹ (1.Transmission Devices Laboratory, Sumitomo Electric Industries, Ltd., Yokohama, Japan)

Keywords:InAs/Gasb type-II superlattices,MWIR,Dark current

InAs/GaSb type-II superlattices (T2SLs) are expected as the material systems for infrared image sensors with high speed and high detectivity. In the conventional pin photodiodes of T2SLs, the dark current components such as diffusion current, generation recombination (G-R) current from the depletion region and tunnel current are present, so pin photodiodes are usually used below 80 K in order to lower the dark currents. Stirling cooler systems with large size are used for cooling down the image sensor. On the other hand, photodiodes of T2SLs with barrier layer effectively suppress some of the dark current components and can be used at higher temperature [1-3]. As the results, photodiode with barrier layer implemented image sensors offers many advantages, especially in low Size, Weight and Power (SWaP). In this study, we fabricated pBiBn photodiodes and the performances were compared with those of the conventional pin photodiodes, where the pBiBn structure has unipolar electron and hole barriers sandwiched in between p contact and absorber region, n contact and absorber region. The cut-off wavelength was 6 µm.