Performance analysis of SnS photodetector using strained SnO2 stacked layer: Numerical simulation and DFT calculations

Abstract

In this work, a new broadband Photodetector (PD) based on strained-SnO2/SnS heterostructure combined with back grooves aspect is proposed. First-principles calculations are carried out to assess the influence of volume reduction using compressive stress on the electronic and optical properties of SnO2 wide band gap material. The obtained results demonstrate the potential of SnO2 under biaxial strain as a junction partner of SnS material, showing a lower band gap of 3.06 eV allowing a favorable band offset with SnS active layer. Moreover, numerical models based on Finite Difference Time Domain (FDTD) technique are developed to analyze the optical performances of strained-SnO2/SnS structure including periodic back grooves at the SnS/glass interface. It is revealed that the proposed device based on combined strained-SnO2/SnS heterostructure and back grooves approach offers the possibility for bridging the gap between extended absorption cutoff wavelength and improved photo-induced carrier extraction capability. The device shows a high ION/IOFF ratio of 78 dB and an enhanced responsivity under UV, visible and NIR lights (171mA/W at 365 nm, 67 mA/W at 550 nm and 93mA/W at 850nm). Therefore, the investigated PD based on strained SnO2/SnS heterostructure and optimized back grooves morphology can offer multiple sensing purposes with low power consumption and low elaboration cost, making it highly appropriate for the emerging optoelectronic applications.