Fabrication of WSe2/WSexSn homojunction for enhanced photoelectric detection application

Two-dimensional transition metal dichalcogenides (2D-TMDs) have emerged as promising candidates for photoelectric-conversion applications due to their excellent optoelectronic properties. However, the conventional chemical synthesis method often requires harsh experimental conditions and expensive equipment. Herein, a hydrothermal synthesis method was reported to fabricate WSe2/WSexSn (Sn-doped WSe2) homojunction for efficient photoelectric detection application. In the experiment, WSe2 nanoflowers were first prepared by a hydrothermal method. Thereafter, Sn dopant was introduced into the WSe2 surface by an intercalated strategy in the hot SnCl2 solution to form the WSe2/WSexSn homojunction. The photo detection performance was evaluated within the wavelength range from 365 nm to 700 nm. It demonstrates that a responsivity of 12.67 mA/W and a detectivity of 1.09 × 108 Jones could be obtained on the most optimal doping concentration under the power density of 3 mW/cm2 @700 nm. Moreover, the WSe2/WSexSn photodetector exhibits relatively good retention and air stability. It shows that the photo response can remain almost unchanged even the devices are kept in the ambient air for 10 days or underwent numerous on/off cycles. All in all, this study provides a facile approach for the low-cost fabrication of large-scale photonic devices in the future.