image: Figure | Induced fit growth of Ga-based semiconductor thin films and multifunctional applications. a, Optical photograph, and scanning electron microscope image of the as-prepared Ga-based semiconductor film. Good uniformity of 1.8 cm × 1.8 cm and compact surface morphology are demonstrated. b, Schematic diagram of the induced fit growth method for GaSb films. The free metal Ga in the as-exfoliated GaOx film promotes the deposition of vapor atoms, subsequently leading to the island growth of the film. With the prolonged growth duration, the gradually becomes compact and uniform. c, multifunctional applications of as-prepared Ga-based semiconductor thin films. Microscale patterning has been successfully demonstrated in the film. As-constructed thin film transistors confirm the p-type conducting behaviors and increased drain-source current with prolonged growth duration. Moreover, as-constructed thin film transistors can mimic typical synaptic behaviors, such as spike timing-dependent plasticity. On the other hand, a 5 × 5-pixel imaging array is constructed by the as-prepared Ga-based semiconductor thin film, showing precise and uniform imaging results. As-constructed thin film photodetectors all exhibit excellent broadband photodetection ability with different growth duration. In a word, these findings underscore a straightforward and effective strategy for the induced fit growth of multifunctional semiconductor thin films.
Credit: Zai-xing Yang et al.
Current fabrication methods for semiconductor thin films, which typically rely on post-synthesis assembly and epitaxial growth, face challenges related to processing complexity and high growth temperatures. These methods are not fully optimized for the demands of modern Internet of Things applications. Consequently, existing semiconductor thin films and their production techniques fail to achieve efficient optoelectronic conversion, robust flexibility, transparency, and synaptic behavior required for future multifunctional applications. Meanwhile, Ga-based semiconductors, as important functional materials, promise high-speed electronic devices, broadband photodetection, and brain-inspired chips. Therefore, there is an urgent need to develop a substrate-independent and scalable approach for Ga-based semiconductor films growth.
In a new paper published in Light: Science & Applications, a team of scientists, led by Professor Zai-xing Yang from School of Physics, State Key Laboratory of Crystal Materials, Shandong University, China, Department of Materials Science and Engineering, City University of Hong Kong, China, and co-workers have developed an analogous approach for the universal growth of Ga-based semiconductor films on functional substrates. The method is inspired by induced fit theory in molecular biology, where a substrate induces a conformational change in an enzyme to facilitate binding. Therefore, Ga-based semiconductor films, including GaSb, GaSe, GaAs, and GaAsSb, can be successfully prepared with controlled thickness and compact surface. The Ga-rich surface of as-prepared GaOx film facilitates the vapor atom deposition, promoting the film growth with weak substrate dependence. The reported film growth method will open new avenues for various functional substrates integration.
Microscale patterning has been successfully demonstrated in the induced fit-grown Ga-based semiconductor films, promising the large-scale optoelectronic device arrays. Moreover, these scientists summarize the various application sceneries of their as-prepared induced fit-grown Ga-based semiconductor films:
“We have successfully extended the utility of as-prepared films to three novel applications: (1) the thin film transistors exhibit typical p-type conductive behavior with a high current density and high hole mobility; (2) when integrated into various functional substrates, as-constructed film photodetectors show excellent broadband photodetection ability, omnidirectional photoresponse, and robust flexibility; and (3) benefiting from the unique interface of as-prepared films, as-constructed film transistors demonstrate impressive synaptic behaviors, promising for neuromorphic computing.”
“Free from traditional substrate lattice matching, this film growth technique paves the way for versatile, multifunctional substrates tailored to diverse future applications.” they added.
“The induced fit growth method provides a universal and substrate-adaptive platform for the growth of high-quality semiconductor films. The method has been expected to inspire new paradigms in flexible electronics, neuromorphic devices, and multifunctional optoelectronic systems, accelerating the development of next-generation wearable and implantable technologies.” the scientists forecast.
Journal
Light Science & Applications
Article Title
Induced fit growth of Ga-based semiconductor thin films for brain-inspired electronics and optoelectronics