Li intercalation modulated photocurrent response in WS<sub>2</sub> optoelectronic devices
Authors: Song Yu-Xin , Li Yu-Qi , Wang Ling-Han , Zhang Xiao-Lan , Wang Chong , Wang Qin-Sheng ,   Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (Ministry of Education), Center for Quantum Physics, School of Physics, Beijing Institute of Technology, Beijing 100081, China
Published: October 2023

<sec>Transition metal dichalcogenides have emerged as a prominent class of two-dimensional layered material, capturing sustained attention from researchers due to their unique structures and properties. These distinctive characteristics render transition metal dichalcogenides highly versatile in numerous fields, including optoelectronics, nanoelectronics, energy storage devices, and electrocatalysis. In particular, the ability to modulate the doping characteristics of these materials plays a crucial role in improving the photoelectric response performance of devices, making it imperative to investigate and understand such effects.</sec><sec>In recent years, the electrochemical ion intercalation technique has emerged as a novel approach for precise doping control of two-dimensional materials. Building upon this advancement, this paper aims to demonstrate the effective doping control of transition metal dichalcogenides devices by utilizing the electrochemical ion intercalation method specifically on thick WS<sub>2</sub> layers. The results show that the conductivity is significantly improved, which is about 200 times higher than the original value, alongside the achievement of efficient and reversible control over the photoelectric response performance is effectively and reversibly controlled by manipulating the gate voltage. One of the key findings in this work is the successful demonstration of the reversible cyclic control of the photoelectric response in WS<sub>2</sub> devices through ion intercalation, regulated by the gate voltage. This dynamic control mechanism showcases the potential for finely tuning and tailoring the performance of photoelectric devices made from two-dimensional materials. The ability to achieve reversible control is especially significant as it allows for a versatile range of applications, enabling devices to be adjusted according to specific requirements and operating conditions.</sec><sec>The implications of this work extend beyond the immediate findings and present a foundation for future investigation into response control of photoelectric devices constructed by using two-dimensional materials through the utilization of the ion intercalation method. By establishing the feasibility and efficacy of this technique in achieving controlled doping and precise modulation of photoelectric response, researchers can explore its potential applications in various technological domains. Furthermore, this research serves as a stepping stone for developing the advanced doping strategies, enabling the design and fabrication of high-performance devices with enhanced functionalities.</sec><sec>In summary, this work showcases the significance of doping control in transition metal dichalcogenide devices and demonstrates the potential of the electrochemical ion intercalation method for achieving precise modulation of their photoelectric response performance. The observed enhancements in electrical conductivity and the ability to reversibly control the photoelectric response highlight the promising prospects of this technique. Ultimately, this work paves the way for future advancements in the field of two-dimensional materials and opens up new way for designing and optimizing photoelectric devices with improved functionality and performance.</sec>