A facile method to fabricated UV–Vis photodetectors based on TiO 2 /Si heterojunction

Abstract Spin coating was used to prepare TiO 2 /Si heterojunction photo-detector using anatase TiO 2 nanoparticles modified with 1,4-butanediol. The heterojunction was formed between the spin coated TiO 2 nanoparticle films (200 nm) and the Si substrates. The heterojuncted structures will facilitate the separation of photo-generated carriers. The large surface-to-volume ratio of TiO 2 nanoparticles will improve the lifetime of photo-generated carriers. Our results show that the photocurrent has a linear relationship to the intensity of UV/visible light when negatively biased at −2 V. The quantum efficiency can reach 137% and 190% at 350 nm and 550 nm, respectively. The response/recovery time is very short (t r and t d