Remarkable enhancement of photoluminescence and photoresponse due to photonic crystal structures based on GeSiSn/Si multiple quantum wells

Abstract

The GeSiSn/Si structures surface with multiple quantum wells (MQWs) was modified by developing photonic crystals (PCs) to increase the photoluminescence and photoresponse near 2 μm. The structural parameters of GeSiSn/Si MQWs obtained by molecular-beam epitaxy were optimized, and PCs were formed. They consisted of a periodic cylindrical hole array. Numerical simulation methods were used to optimize the hole depth, which makes it possible to effectively excite quasi-guided modes and not affect the active layer including GeSiSn/Si MQWs. The increase of the photoluminescence (PL) signal related to vacancy complexes was observed for all samples with the PC structure. The maximum PL amplification of about 5 times at the wavelength near 2 μm was demonstrated. The annealing of PC structures with GeSiSn/Si MQWs resulted in the appearance of PL associated with interband optical transitions. The PL enhancement was observed by almost an order of magnitude in the narrow wavelength range with the PL maximum near 1.8 μm. Based on Ge0.84Si0·076Sn0·084/Si MQWs p-i-n photodiodes with the PC, the photoresponse increase was shown in the wide wavelength range up to 1.8 μm.