Pressure-induced enhancement of optoelectronic properties in PtS2

• 来源期刊: 中国物理B（英文版）
• 关键词: high pressure optoelectronic properties transition metal disulfide
• 年，卷（期）: 2018,（6）
• 页码范围: 343-347
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/6/066201

摘要

PtS2,which is one of the group-10 transition metal dichalcogenides,attracts increasing attention due to its extraordinary properties under external modulations as predicted by theory,such as tunable bandgap and indirect-to-direct gap transition under strain;however,these properties have not been verified experimentally.Here we report the first experimental exploration of its optoelectronic properties under external pressure.We find that the photocurrent is weakly pressuredependent below 3 GPa but increases significantly in the pressure range of 3 GPa-4 GPa,with a maximum ～ 6 times higher than that at ambient pressure.X-ray diffraction data shows that no structural phase transition can be observed up to 26.8 GPa,which indicates a stable lattice structure of PtS2 under high pressure.This is further supported by our Raman measurements with an observation of linear blue-shifts of the two Raman-active modes to 6.4 GPa.The pressure-enhanced photocurrent is related to the indirect-to-direct/quasi-direct bandgap transition under pressure,resembling the gap behavior under compression strain as predicted theoretically.