High-Performance InGaN p-i-n Photodetectors Using LED Structure and Surface Texturing

High-performance InGaN-based p-i-n photodetectors (PDs) were fabricated using a typical light-emitting diode (LED) epitaxial structure and surface texturing. A multiple-quantum-well active-layer structure effectively mitigates the indium clustering problem and achieves a high rejection ratio and scalability. Two types of surface texturing for enhancing spectral responsivity were fabricated and compared. High responsivities of 0.21, 0.23, and 0.24 A/W were attained at a wavelength of 388 nm and the biases of 0, -1.5, and -3.0 V, respectively, corresponding to external quantum efficiencies (EQEs) of 67%, 73%, and 78%. And the dark current was below 10 pA at zero bias. To the best of our knowledge, the responsivity reported in this letter is the highest for InGaN-based p-i-n PDs. Moreover, the sample with a surface-textured p-GaN layer has 50%-85% higher EQE at wavelengths between 335 and 365 nm and flatter spectral responsivity than did the other examined sample. High cost performance, low operating voltage, and LED-process-compatible PDs were obtained.