[Display omitted] • Design neo-heterojunction BiFe 1- x Zn x O 3 /NiO as visible-light-active photodetector. • Fe-site substitution strategy is used to reduce energy bandgap of BFZO to 2.0 eV. • Photoresponse time constants of BFZO/NiO are optimized less than one millisecond. • Interface between BFZO and NiO accelerates charge transit and boosts response speed. • BFZO/NiO shows great photoresponse speed compared to other congeneric devices. Although BiFeO 3 (BFO) is regarded as one of up-and-coming ferroelectric oxides in the field of semiconducting devices due to its anomalous optoelectronic characteristics, is it possible to exploit its potential in the application of photodetection in visible band (Vis)? To answer this question, we firstly follow the recognized strategy of Fe-site substitution by involving zinc ions in BFO, i.e. synthesize BiFe 1- x Zn x O 3 (BFZO) by sol–gel technique and successfully shrink its energy bandgap (E g) from 2.3 eV of pure BFO down to circa 2.0 eV; moreover, we innovatively integrate hole-transporter NiO and constitute BFZO/NiO heterostructure to further accelerate charge carrier transitions. Going through systematical investigation on E g and leakage current of BFZO films with Zn ratio optimization, as well as energy band alignment between BFZO and NiO, the splendid photo-response speed of BFZO/NiO heterojunction is achieved. The best response time constants of photocurrent rising and decay are optimized to 0.36 ms and 0.49 ms, which are two order-of-magnitude faster than pure-BFO/NiO and one order-of-magnitude faster than single BFZ 0.8 O film. Such neo-heterojunction has overwhelming photoresponse properties compared to other congeneric BFO/metal-ion-doped-BFO photodetectors reported elsewhere. Hereby, it portends a promising future of conventional wide-bandgap ferroelectric oxides in the application of up-to-date high-speed Vis detection. [ABSTRACT FROM AUTHOR]