Observation of room temperature optical absorption in InP/GaAs type-II ultrathin quantum wells and quantum dots

被引:2
作者
Singh, S. D. [1 ]
Porwal, S. [1 ]
Mondal, Puspen [1 ]
Srivastava, A. K. [1 ]
Mukherjee, C. [1 ]
Dixit, V. K. [1 ]
Sharma, T. K. [1 ]
Oak, S. M. [1 ]
机构
[1] Raja Ramanna Ctr Adv Technol, Indore 452013, Madhya Pradesh, India
关键词
SURFACE PHOTOVOLTAGE SPECTROSCOPY; INAS; DEPENDENCE; TRANSITION;
D O I
10.1063/1.4882075
中图分类号
O59 [应用物理学];
学科分类号
摘要
Room temperature optical absorption process is observed in ultrathin quantum wells (QWs) and quantum dots (QDs) of InP/GaAs type-II band alignment system using surface photovoltage spectroscopy technique, where no measurable photoluminescence signal is available. Clear signature of absorption edge in the sub band gap region of GaAs barrier layer is observed for the ultrathin QWs and QDs, which red shifts with the amount of deposited InP material. Movement of photogenerated holes towards the sample surface is proposed to be the main mechanism for the generation of surface photovoltage in type-II ultrathin QWs and QDs. QDs of smaller size are found to be free from the dislocations as confirmed by the high resolution transmission electron microscopy images. (C) 2014 AIP Publishing LLC.
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页数:6
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