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.