Synthesis and Photoresponse of Large GaSe Atomic Layers
2013; American Chemical Society; Volume: 13; Issue: 6 Linguagem: Inglês
10.1021/nl4010089
ISSN1530-6992
AutoresSidong Lei, Liehui Ge, Zheng Liu, Sina Najmaei, Gang Shi, You Ge, Jun Lou, Róbert Vajtai, Pulickel M. Ajayan,
Tópico(s)Chalcogenide Semiconductor Thin Films
ResumoWe report the direct growth of large, atomically thin GaSe single crystals on insulating substrates by vapor phase mass transport. A correlation is identified between the number of layers and a Raman shift and intensity change. We found obvious contrast of the resistance of the material in the dark and when illuminated with visible light. In the photoconductivity measurement we observed a low dark current. The on-off ratio measured with a 405 nm at 0.5 mW/mm(2) light source is in the order of 10(3); the photoresponsivity is 17 mA/W, and the quantum efficiency is 5.2%, suggesting possibility for photodetector and sensor applications. The photocurrent spectrum of few-layer GaSe shows an intense blue shift of the excitation edge and expanded band gap compared with bulk material.
Referência(s)