Liu Ji Hong, Qiao Shuang, Liang BaoLai, Wang ShuFang, Fu GuangSheng
Opt Express. 2017 Feb 20;25(4):A166-A175. doi: 10.1364/OE.25.00A166.
For photovoltaic effect (PE), both barrier height and carrier lifetime are all very important factors. However, how to distinguish their contributions to the PE is very difficult. In this paper, we prepared a series of GaAs/AlGaAs two dimensional electron gas (2DEG) with typical AlGaAs doping concentration of 0.6 × 10/cm, 1.2 × 10/cm, and 2.5 × 10/cm, respectively (sample number: #1, #2, #3), and studied their lateral photovoltaic effects (LPEs). It is found that their position sensitivities all increase with both laser wavelength and laser power. However, the position sensitivity exhibits a non-monotonic behavior with increasing doping concentration, which can be mainly ascribed to the doping concentration-dependent carrier lifetime, especially in the low power regime. With increasing laser power gradually, the position sensitivity difference between sample #1 and sample #2 is still large and increases a little, while the position sensitivity of sample #3 approaches to that of sample #2, suggesting that the doping concentration-dependent barrier height also starts to play an important role in the high power regime. Our results will provide important information for the design and development of novel and multifunctional PE devices.
对于光伏效应（PE）而言，势垒高度和载流子寿命都是非常重要的因素。然而，如何区分它们对光伏效应的贡献却非常困难。在本文中，我们制备了一系列典型的AlGaAs掺杂浓度分别为0.6×10/cm、1.2×10/cm和2.5×10/cm的GaAs/AlGaAs二维电子气（2DEG）（样品编号：#1、#2、#3），并研究了它们的横向光伏效应（LPEs）。结果发现，它们的位置灵敏度均随激光波长和激光功率的增加而提高。然而，位置灵敏度随掺杂浓度的增加呈现出非单调行为，这主要归因于与掺杂浓度相关的载流子寿命，尤其是在低功率状态下。随着激光功率逐渐增加，样品#1和样品#2之间的位置灵敏度差异仍然很大且略有增加，而样品#3的位置灵敏度接近样品#2的，这表明与掺杂浓度相关的势垒高度在高功率状态下也开始发挥重要作用。我们的结果将为新型多功能光伏效应器件的设计和开发提供重要信息。
