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Fabrication of a p-n Heterojunction Using Topological Insulator Bi2Te3-Si and Its Annealing Response

IR@NPL: CSIR-National Physical Laboratory, New Delhi

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Title Fabrication of a p-n Heterojunction Using Topological Insulator Bi2Te3-Si and Its Annealing Response
 
Creator Ahmad, Faizan
Singh, Rashmi
Misra, Prasanna Kumar
Kumar, Naresh
Kumar, Rachna
Kumar, Pramod
 
Subject Electronics and Electrical Engineering
Materials Science
Applied Physics/Condensed Matter
 
Description A junction device has been fabricated by growing p-type Bi2Te3 topological insulator (TI) film on an n-type silicon (Si) substrate using a thermal evaporation technique. Annealing using different temperatures and durations was employed to improve the quality of the film, as confirmed by microstructural study using x-ray diffraction (XRD) analysis and atomic force microscopy (AFM). The p-n diode characteristics of the junction devices were studied, and the effect of annealing investigated. An improved diode characteristic with good rectification ratio (RR) was observed for devices annealed for longer duration. Reduction in the leakage or reverse saturation current (I-R) was observed with increase in the annealing temperature. The forward-bias current (I-F) dropped in devices annealed above 400 degrees C. The best results were observed for the sample device annealed at 450 degrees C for 3h, showing figure of merit (FOM) of 0.621 with RR approximate to 504 and = 0.25 mu A. In terms of ideality factor, the sample device annealed at 550 degrees C for 2h was found to be the best with n = 6.5, RR approximate to 52.4, I-R = 0.61 mu A and FOM = 0.358. The majority-carrier density (N-A) in the p-Bi2Te3 film of the heterojunction was found to be on the order of 10(9)/cm(3) to 10(11)/cm(3), quite close to its intrinsic carrier concentration. These results are significant for fundamental understanding of device applications of TI materials as well as future applications in solar cells.
 
Publisher Institute of Electrical and Electronics Engineers
 
Date 2018-12
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://npl.csircentral.net/3972/1/Ahmad2018_Article_FabricatioNOfAPNHeterojuNctioN.pdf
Ahmad, Faizan and Singh, Rashmi and Misra, Prasanna Kumar and Kumar, Naresh and Kumar, Rachna and Kumar, Pramod (2018) Fabrication of a p-n Heterojunction Using Topological Insulator Bi2Te3-Si and Its Annealing Response. Journal of Electronic Materials , 47 (12). pp. 6972-6983. ISSN 0361-5235
 
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