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\times 10^{-{10}}$ A/cm2 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 $1.14\times 10^{-{11}}$ W and $2.77\times 10^{{11}}$ cm $\cdot $ Hz $^{{0.5}}\,\,\cdot \,\,\text{W}^{-{1}}$ , respectively. The high-performance PD achieved is believed to be related to the high crystalline quality of the InGaN epilayer.