Significantly Increased Photoresponsivity of WSe 2 ‐Based Transistors through Hybridization with Gold‐Tetraphenylporphyrin as Efficient n ‐Type Dopant

• Published in: Advanced electronic materials Vol. 5; no. 4
• Main Authors: Lee, Dong Seop, Kim, Jun Young, Shin, Dae Yong, Lee, Yongjun, Kim, Jeongyong, Lee, Suk Joong, Joo, Jinsoo
• Format: Journal Article
• Language: English
• Published: 01-04-2019
• ISSN: 2199-160X; 2199-160X
• DOI: 10.1002/aelm.201800802

The control of electrical and optical characteristics of 2D transition‐metal dichalcogenides (TMDCs) through charge doping is essential to optimize the performances of optoelectronic devices based on TMDCs. In this study, a few‐layer tungsten diselenide (WSe
2
) is hybridized with organic gold(III)‐tetraphenylporphyrin (Au‐TPP) using a simple drop‐casting method. Nanoscale optical characteristics, measured by laser confocal microscopy, reveal that the photoluminescence intensity and exciton lifetime of Au‐TPP decrease after the hybridization with WSe
2
, which suggests the charge transfer from Au‐TPP to WSe
2
. For optoelectronic applications, photoresponsive field‐effect transistors (FETs) based on pristine WSe
2
and WSe
2
/Au‐TPP hybrids are fabricated and compared. After the hybridization with Au‐TPP, the charge transport characteristics of the WSe
2
‐based FETs change to severe n‐type characteristics including a negative shift of the threshold voltage and increase in electron mobility. Significantly enhanced photoresponsivities (up to 310 times) are observed for the WSe
2
/Au‐TPP‐based FETs owing to their efficient light absorption and charge transfer from Au‐TPP to WSe
2
.