He Jiaqi, He Dawei, Wang Yongsheng, Zhao Hui
Opt Express. 2015 Dec 28;23(26):33370-7. doi: 10.1364/OE.23.033370.
We report a transient absorption study of photocarrier dynamics in transition metal dichalcogenide alloy, Mo0.5W0.5S2. Photocarriers were injected by a 400-nm pump pulse and detected by a 660-nm probe pulse. We observed a fast energy relaxation process of about 0.7 ps. The photocarrier lifetime is in the range of 50 - 100 ps, which weakly depends on the injected photocarrier density and is a few times shorter than MoS2 and WS2, reflecting the relatively lower crystalline quality of the alloy. Saturable absorption was also observed in Mo0.5W0.5S2, with a saturation energy fluence of 32 μJ cm(-2). These results provide important parameters on photocarrier properties of transition metal dichalcogenide alloys.
我们报道了对过渡金属二硫属化物合金Mo0.5W0.5S2中光载流子动力学的瞬态吸收研究。光载流子由400 nm的泵浦脉冲注入，并由660 nm的探测脉冲检测。我们观察到一个约0.7 ps的快速能量弛豫过程。光载流子寿命在50 - 100 ps范围内，其对注入的光载流子密度的依赖性较弱，且比MoS2和WS2短几倍，这反映了该合金相对较低的晶体质量。在Mo0.5W0.5S2中也观察到了饱和吸收，饱和能量通量为32 μJ cm(-2)。这些结果提供了关于过渡金属二硫属化物合金光载流子特性的重要参数。
