Current–Voltage Characteristics of n-B-p Structures with Absorbing In0.53Ga0.47As Layer

Abstract

A topical problem of photoelectronics is the development of array photodetector devices of the near infrared spectral range based on the InxGa1–xAs/InP epitaxial layers of the megapixel format. In this paper, we present the results of studies of current–voltage characteristics of photosensitive elements in arrays of the 320 × 256 format with a step of 30 μm based on heteroepitaxial structures with an InGaAs absorbing layer on InP short-wave infrared substrates. Arrays of photosensitive elements (PSEs) are fabricated using planar, mesa, and mesa planar technologies based on nB(Al0.48In0.52As)p-structures. In arrays produced using the mesa planar technology based on nB(Al0.48In0.52As)p-structures, small dark current and ampere–watt sensitivity to IR radiation of the 1–1.7 μm range are shown to combine successfully at low bias voltages. Electrophysical parameters of functional layers of initial heteroepitaxial n-B-p structures affect efficiently the dark currents and ampere–watt sensitivity of the array elements. Based on these studies, parameters of the n-B(Al0.48In0.52As) functional layers of p-structures were optimized and high-efficiency photodiode arrays of the 320 × 256 format with a step of 30 μm and structures of the 640 × 512 format with a step of 15 μm were fabricated with a defectiveness not exceeding 0.5%.