Two-dimensional (2D) van der Waals (vdW) heterostructures herald new opportunities for conducting fundamental studies of new physical/chemical phenomena and developing diverse nanodevice applications. In particular, vdW heterojunction p-n diodes exhibit great potential as high-performance photodetectors, which play a key role in many optoelectronic applications. Here, we report on 2D MoTe2/MoS2 multilayer semivertical vdW heterojunction p-n diodes and their optoelectronic application in self-powered visible-invisible multiband detection and imaging. Our MoTe2/MoS2 p-n diode exhibits an excellent electrical performance with an ideality factor of less than 1.5 and a high rectification (ON/OFF) ratio of more than 104. In addition, the photodiode exhibits broad spectral photodetection capability over the range from violet (405 nm) to near-infrared (1310 nm) wavelengths and a remarkable linear dynamic range of 130 dB within an optical power density range of 10-5 to 1 W/cm2 in the photovoltaic mode. Together with these favorable static photoresponses and electrical behaviors, very fast photo- and electrical switching behaviors are clearly observed with negligible changes at modulation frequencies greater than 100 kHz. In particular, inspired by the photoswitching results for periodic red (638 nm) and near-infrared (1310 nm) illumination at 100 kHz, we successfully demonstrate a prototype self-powered visible-invisible multiband image sensor based on the MoTe2/MoS2 p-n photodiode as a pixel. Our findings can pave the way for more advanced developments in optoelectronic systems based on 2D vdW heterostructures.
Bibliographical noteFunding Information:
D.K.H. acknowledges financial support from the Korea Institute of Science and Technology (KIST) Institution Program (Grant Nos. 2E30100, 2E30420, and 2V07850) and from the National Research Foundation of Korea (NRF) (Grant No. 2019R1A2B5B02003419). M.-C.P. acknowledges financial support from the Ministry of Culture, Sports and Tourism (MCST) and the Korea Creative Content Agency (KOCCA) under the Culture Technology (CT) Research & Development Program 2017 (R2017060005, Development of AR Platform based on Hologram). S.I. acknowledges financial support from NRF (SRC program: Grant No. 2017R1A5A1014862, vdWMRC Center).
All Science Journal Classification (ASJC) codes
- Materials Science(all)