High-Performance InGaN/GaN Photodetectors With 30-Period Multiple Quantum Wells

A high-performance InGaN/GaN multiple quantum well (MQW) p-i-n photodetector (PD) is fabricated on patterned sapphire substrates (PSSs). The fabricated PD exhibits a low dark current density of <2.0 x 10(-10) A/cm(2) under a bias voltage of -2 V, with a high photocurrent to dark current contrast ratio of over 10(6). Furthermore, the peak responsivity at the wavelength of 395 nm reaches 0.18 A/W at -10 V, corresponding to a maximum quantum efficiency of approximately 56%. In addition, the noise equivalent power (NEP) and normalized detectivity were found to be 1.14 x 10(-11) W and 2.77 x 10(11) cm center dot Hz(0.5) center dot W-1, respectively. The high-performance PD achieved is believed to be related to the high crystalline quality of the InGaN epilayer.