Open Access Nano Express

Quantum dot-doped porous silicon metal–semiconductor metal photodetector

Chia-Man Chou1, Hsing-Tzu Cho2, Vincent K S Hsiao2*, Ken-Tye Yong3 and Wing-Cheung Law4

Author Affiliations

1 Division of Pediatric Surgery, Department of Surgery, Taichung Veterans General Hospital, 160 sec. 3 Chung-Kang Rd, Taichung, 40705, Taiwan

2 Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, No. 1, University Rd, Puli, NanTou, 54561, Taiwan

3 School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang, 639798, Singapore

4 Institute for Lasers, Photonics, and Biophotonics, University at Buffalo, The State University of New York, Buffalo, NY, 14260-4200, USA

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Nanoscale Research Letters 2012, 7:291  doi:10.1186/1556-276X-7-291

Published: 6 June 2012


In this paper, we report on the enhancement of spectral photoresponsivity of porous silicon metal–semiconductor metal (PS-MSM) photodetector embedded with colloidal quantum dots (QDs) inside the pore layer. The detection efficiency of QDs/PS hybrid-MSM photodetector was enhanced by five times larger than that of the undoped PS-MSM photodetector. The bandgap alignment between PS (approximately 1.77 eV) and QDs (approximately 1.91 eV) facilitates the photoinduced electron transfer from QDs to PS whereby enhancing the photoresponsivity. We also showed that the photoresponsitivity of QD/PS hybrid-MSM photodetector depends on the number of layer coatings of QDs and the pore sizes of PS.

Porous silicon; Quantum dots; Photodetector