An AlAs/InGaAs/AlAs/InAlAs double-barrier quantum well infrared photodetector operating at 3.4 μm and 205 K

A high-performance n-type AlAs/InGaAs/AlAs/InAlAs double-barrier quantum well infrared photodetector grown on InP with photovoltaic (PV) and photoconductive (PC) dual-mode operation has been fabricated and characterized in this work. The PV and PC detection scheme employs the intersubband transition from the ground bound state to the quasibound excited state in the double-barrier well. The peak responsivities for the PV mode at zero bias and PC mode at Vb=−3 V were found to be 19 and 159 mA/W at λp=3.4 μm and T=77 K, respectively. The corresponding background limited performance (BLIP) detectivity (DBLIP*) was given by 8.9×1010 cm Hz1/2/W for the PV mode and non-BLIP D*=5.36×1010 cm Hz1/2/W for the PC mode. This device is capable of operating up to 205 K with good performance characteristics.