ABSTRACT By virtue of wide bandgaps, high visible transparency, and excellent cost‐performance ratio, metal oxides exhibit distinct advantages for photodetectors. However, precise, designable, and multi‐material‐compatible fabrication of metal oxide photodetectors is still challenging. In this work, we propose a controllable direct laser printing strategy to realize the in situ growth of titanium oxide (TiO 2 ) micro/nanostructures and the designable fabrication of broadband photodetectors. A stable TiO 2 precursor ink has been developed. The microscopic growth of TiO 2 under laser exposure is elucidated by simulation and experiments. The effects of laser printing parameters on the morphology of printed TiO 2 micro/nanostructures are systematically investigated. Direct laser printing of TiO 2 with controllable morphology and designable patterns is realized. On this basis, TiO 2 ‐based ultraviolet photodetectors from laser printing are achieved. Furthermore, to demonstrate the multi‐material integration capability of this direct laser printing strategy, cadmium oxide (CdO) is integrated with TiO 2 to construct a TiO 2 /CdO composite photodetector, enabling broadband photo‐response from the ultraviolet to the near‐infrared region. This work provides a customizable, high‐precision, and lithography‐free route for metal oxide optoelectronics.
Su et al. (Tue,) studied this question.