Engineering Oxygen Vacancies in CeO₂ for High-Performance UV-Vis Photodetector

Abstract

In this letter, a solution combustion synthesized (SCS) CeO2 -based high-performance wideband photodetector (PD) is reported. The SCS method was categorically chosen to narrow the bandgap of synthesized CeO2 via nitrogen or carbon doping and employ the higher level of oxygen vacancies in photodetection. The PD's structure is composed of p-Si/Al/CeO2 /Ag layers, where T1 and T2 are Al and Ag -based electrodes, respectively. The fabricated PD exhibits excellent photodetection capability between 350 nm to 850 nm with a peak responsivity of 12.42 A.W−1 at 411 nm. The highest measured value of external quantum efficiency (EQE) and specific detectivity ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D^{*}$ </tex-math></inline-formula> ) of the PD are 24.65% at 401 nm and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.57 \times 10^{10}$ </tex-math></inline-formula> Jones at 501 nm, respectively. The fabricated PD's rise and fall times are measured to be approximately 27 ms and 16 ms, respectively. An experimental application of the proposed PD through a simple visible lightwave communication (VLC) system is also shown.