Hongyun Chen, Yu Lu, Chen Li, Xingyuan Zhao, Xiuxing Zhang, Zhixiang Zhang, and Linbao Luo*
Author Affiliations
School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei, Anhui 230601, Chinashow less
Fig. 1. Diagram of device structure and material characterization. (a) Diagram of device structure, inset shows built-in electric field at PtSe2/TiO2 surface; (b) top view SEM image of TiO2 NRs, inset shows magnification of SEM image; (c) cross-sectional view SEM image of TiO2 NRs; (d) XRD pattern of FTO and TiO2 NRs grown on FTO; (e) SEM image of PtSe2 film; (f) height profile of PtSe2 film, inset shows AFM image of PtSe2
Fig. 2. Structure and composition of two-dimensional material PtSe2. (a) HRTEM image; (b) Raman spectrum; (c) XPS image of Pt 4 f; (d) XPS image of Se 3 d
Fig. 3. Response curves to 365 nm light and energy band diagram of proposed device. (a) I-V curve, inset shows I-V characteristic of dark current in logarithmic coordinates; (b) photo response under 365 nm light illumination at bias voltage of -1.0 V; (c) energy band diagram; (d) photo response of device for about two hundreds cycles of operation; (e) photo response of device before and after 5 weeks in air ambient condition
Fig. 4. Electrical performance under different optical power densities. (a) I-V curve; (b) photo response of device at bias voltage of -1.5 V; (c) fitting curve of photocurrent and optical power density; (d) relationship between Ilight/Idark and optical power density at bias voltage of -1.5 V; (e) change of responsivity and specific detection rate with incident light power density; (f) relationship between ηEQE and optical power density at bia
Fig. 5. Light absorption and response of device. (a) Spectral response of device; (b) absorption spectra of TiO2, PtSe2, and device; (c) response curve of device under 365 nm irradiation with a frequency of 1 Hz; (d) rise time and fall time of device
Fig. 6. Simple imaging of device. (a) Schematic of UV imaging system; (b) 2D current map under 365 nm light illumination
Device structure | Ilight/Idark | R(A/W) | D* /Jones | Wavelength /nm (Voltage /V) |
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SLG-TiO2 heterojunction[21] | 6.8×104 | 0.0016 | 7.29×1010 | 405(-10) | TiO2 NRs/GO[22] | 2 | 0.0483 | 2.26×1011 | 380(3) | TiO2 nanocrystals/PFH structure[23] | ~103 | 0.0546 | 3.94×1011 | 365(0) | FTO/TiO2/Mo | ~102 | 45.4400 | 1.93×1013 | 360(-2.2) | SLG/TiO2 NRs/FTO[25] | 4×103 | 12.3000 | 3.50×1013 | 385(-5) | PtSe2/TiO2 NRs | 5.5×104 | 0.0569 | 8.36×1011 | 365(-1.5) |
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Table 1. Comparison of parameters of PtSe2/TiO2 NRs array photodetector and other TiO2-based heterojunction devices