High Gain and Broadband Absorption Graphene Photodetector Decorated with Bi2Te3 Nanowires.

Tae Jin Yoo,Byoung Hun Lee,Min Gyu Kwon,Wan Sik Kim,Ji Young Jo,Cihyun Kim,Kyoung Eun Chang

doi:10.3390/nano11030755

Abstract

A graphene photodetector decorated with Bi2Te3 nanowires (NWs) with a high gain of up to 3 × 104 and wide bandwidth window (400–2200 nm) has been demonstrated. The photoconductive gain was improved by two orders of magnitude compared to the gain of a photodetector using a graphene/Bi2Te3 nanoplate junction. Additionally, the position of photocurrent generation was investigated at the graphene/Bi2Te3 NWs junction. Eventually, with low bandgap Bi2Te3 NWs and a graphene junction, the photoresponsivity improved by 200% at 2200 nm (~0.09 mA/W).

Highlights

Graphene has attracted much interest for optoelectronic applications due to its unique photonic properties, such as its broad bandwidth absorption, short carrier lifetime, and high gain by the carrier multiplication process [1,2,3,4,5,6]
Alternative approaches combining a graphene photodetector with additional light absorption materials have been reported [11,12,13,14]
In the organic-graphene photodetector, a photoresponsivity of ~106 A/W was obtained in the 600–1500 nm region [14]

Summary

Introduction

Graphene has attracted much interest for optoelectronic applications due to its unique photonic properties, such as its broad bandwidth absorption, short carrier lifetime, and high gain by the carrier multiplication process [1,2,3,4,5,6]. When an absorber is placed on a graphene channel, it limits the applicable wavelength because the bandgap of an absorber determines the photon absorption range. The absorber and deposition process should be chosen very carefully In this sense, low bandgap Bi2 Te3 may represent a good absorber candidate for a graphene photodetector. Gao et al reported a graphene photodetector decorated with Bi2 Te3 nanoplates, which was grown by thermal chemical vapor deposition (CVD) and achieved a 35 A/W photoresponsivity with a gain of up to 83 at 532 nm [19]. A broadband absorption range from 400 to 2200 nm and high photoconductive gain of 3 × 104 were obtained

Materials and Methods

Discussion

Te3 980

Conclusions

4.Supplementary