High in content InGaAs near-infrared detectors: growth, structural design and photovoltaic properties

The design of novel structural material is an effective way to improve photodetection device performance. In this paper, the fabrication and performance of high In content InGaAs detectors were investigated. Using the two-step growth method, mismatch defect was effectively inhibited even with larger lattice mismatch at the interface. Meanwhile, the spectral response can cover the entire near-infrared region at room temperature. Through experiments and simulation, the optoelectronic properties of detector with different materials in the p-region are explored, elucidating the critical role of cap material in the transport properties of carriers. Compared to the typical InP cap detector, the InAsP cap detector shows better device performance. Also the dark current mechanism is analyzed on the basis of bias–temperature relation, and the result shows that the tunneling current plays a key role at high bias or low temperature. The introduction of a novel InGaAs detector provides a potential application to the development of near-infrared detection.