Photoelectrochemical Application And Charge Transport Dynamics Of A Water-Stable Organic-Inorganic Halide (C6h4nh2cucl2i) Film In Aqueous Solution

A water-stable thin film composed of C6H4NH2CuCl2I was fabricated using spin-coating precursor solutions that dissolved equimolar amounts of C6H4NH2I and CuCl2 in N,N-dimethylformamide. Photoelectrochemical characteristics show that the C6H4NH2CuCl2I film demonstrated a stable photocurrent (similar to 1 mu A/cm(2)) in an aqueous solution under white light (11.5 mW/cm(2)) even after 3000 s, while exhibiting a photon-to-current efficiency of 0.093% under AM1.5 (100 mW/cm(2)) illumination. However, these values were significantly lower than those of the CH3NH3PbX3 (X = I, Cl) film in solid devices. The electron diffusion length L(e-) (373 nm) and hole diffusion length L(h(+)) (177 nm) in the C6H4NH2CuCl2I photoelectrode were significantly lower than those of CH3NH3PbX3, limiting the photoelectrochemical and photocatalysis performances. Moreover, L(h(+)) was shorter than L(e(-)) in the C6H4NH2CuCl2I photoelectrode, resulting in the hole-collecting efficiency [eta(c)(h(+))] being lower than the electron-collecting efficiency [eta(c)(e(-))]. A CuO interlayer was introduced as a hole transport layer for the C6H4NH2CuCl2I photoelectrode, which improved L(h(+)) and eta(c)(h(+)).