Drs. Longwei Ding

Center for Nanoscale Characterization and Devices, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, China

Authors | Longwei Ding , Nishuang Liu , Luying Li , Xing Wei , Xianghui Zhang , Jun Su , Jiangyu Rao , Congxing Yang , Wenzhi Li , Jianbo Wang , Haoshuang Gu , and Yihua Gao Email | gaoyihua@hust.edu.cn

ApplicationGraphene-Skeleton Heat-Coordinated and Nanoamorphous- Surface-State Controlled Pseudo-Negative-Photoconductivity of Tiny SnO 2 Nanoparticles
AuthorsLongwei Ding , Nishuang Liu , Luying Li , Xing Wei , Xianghui Zhang , Jun Su , Jiangyu Rao , Congxing Yang , Wenzhi Li , Jianbo Wang , Haoshuang Gu , and Yihua Gao
JournalAdvanced Materials. 2015
PublicationFull Publication Here – DOI: 10.1002/adma.201500804

Graphene-Skeleton Heat-Coordinated and Nanoamorphous- Surface-State Controlled Pseudo-Negative-Photoconductivity of Tiny SnO 2 Nanoparticless

Abstract: SnO2 nanoparticles display a pseudo-negative-photoconductivity (PsdNPC) effect, which shows that their resistance increases under light irradiation via a heating effect. The PsdNPC originates from intensive electron scattering of the nanoamorphous surface state of the SnO2nanoparticles, resulting in a small inner current and a large absorption of moisture, leading to a large surface current. Graphene as the inner skeleton can shorten the response and recovery times.

IMAGE RIGHT: The schematic for working PsdNPC mechanism. a) The schematic for combining PPC effect by exciting electrons and the NPC effect by heating for an optoelectronic device. b) A thermodynamic 1D Fourier model for analyzing the heat transfer of the device under light irradiation heating. c) The schematic of shortening the response time of heating effect by decreasing the sizes of the device and the irradiation beam diameter, and increasing the thermal conductivity k of its substrate. d) Graphene can be used to decrease the response time because of its connected architectures, highest heat conductivity, and thus good heat coordination between different nanoparticles.

The SnO 2 nanoparticle has an amorphous surface shell yellow) and crystallized core (purple). e,f) The moisture molecules are released and absorbed with temperature increase and decrease, and surface conductivity becomes worse and better, respectively.

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