A two-dimensional Te/ReS₂ van der Waals heterostructure photodetector with high photoresponsivity and fast photoresponse

Abstract

Two-dimensional (2D) semiconductors are the building blocks for high-performance optoelectronic devices. However, the performance of photoconductive photodetectors based on 2D semiconductors are hampered by the large dark current. Herein, a...

Symmetry-Reduction Enhanced Polarization-Sensitive Photoresponse Based on One-Dimensional van der Waals Materials

“…41 According to the measured noise power spectral density of the Nd 2 Pd 1−x Se 5 photodetector in Figure S7, the Nb 2 Pd 1−x Se 5 photodetector exhibits decreased R (D*) from 1 A/W (4.23 × 10 8 Jones) to 0.2 A/W (8.95 × 10 7 Jones) when the power density increases from 0.45 μW/μm 2 to 6.93 μW/μm 2 , which is probably attributed to the decreased recombination of the photoexcited carriers under weak laser illumination. 24,42 As shown in Figure S8 in the Supporting Information, the maximum EQE of the Nb 2 Pd 1−x Se 5 photodetector reaches 196%, indicating the device has good photoelectric conversion efficiency. 43 The greater than 100% EQE is probably contributed by the combination of a photoconductive effect and photogating effect.…”

“…35 Moreover, the fast photoresponse of the Nb 2 Pd 1−x Se 5 photodetector could be attributed to the following reasons: (1) The relatively large thickness of Nb 2 Pd 1−x Se 5 nanowires can suppress the scattering of photoinduced carriers. 42 (2) The ohmic contact between electrodes and Nb 2 Pd 1−x Se 5 nanowires ensures the photogenerated carriers drift freely through the electrode− Nb 2 Pd 1−x Se 5 interface. 45 (3) The fast carrier mobility could also contribute to the fast photoresponse speed.…”

“…However, the contribution of the photogating effect is greatly suppressed under negative gate voltage due to the compensation of photogenerated holes when applying the negative gate voltage . Moreover, the fast photoresponse of the Nb 2 Pd 1– x Se 5 photodetector could be attributed to the following reasons: (1) The relatively large thickness of Nb 2 Pd 1– x Se 5 nanowires can suppress the scattering of photoinduced carriers . (2) The ohmic contact between electrodes and Nb 2 Pd 1– x Se 5 nanowires ensures the photogenerated carriers drift freely through the electrode–Nb 2 Pd 1– x Se 5 interface .…”

A high-performance long-wave infrared photodetector based on a WSe2/PdSe2 broken-gap heterodiode

“…The increase in I SC and V OC is attributed to the increasing number of photogenerated carriers with increasing laser intensities. 47 Fig. 2c shows the temporal photovoltaic response of the WSe 2 / PdSe 2 heterodiode device under a 637 nm laser with the incident light power varying from 0.41 µW to 6.09 µW.…”

Realizing Ultrafast Response Speed for Self-Powered Photodetectors with a Molecular-Doped Lateral InSe Homojunction

“…This suggests that there are fewer carrier trap states between the Fermi level and the conduction band edge, and the photogenerated charge pairs are less impeded during their efficient motion in the InSe material. This is a better linear fit compared to previous results. − Moreover, the photosensitivity LDR was calculated to be 75 dB according to the equation of LDR = 20 log (I ph /I dark ) . The relatively high LDR means stable responsiveness from low to high light ranges and is expected to be used in high-sensitivity photodetection applications.…”