TiO2/nanoporous silicon hybrid contact for heterojunction crystalline solar cell

Abstract

The conventional solar cell architectures include a p–n junction of c-Si sandwiched by rear and front contacts. The conventional approach features a complex as well as expensive procedure. Here, we propose a new architecture for p–n heterojunction solar cells prepared by a simple and cost-effective procedure. In this regard, (1) a silicon wafer underwent surface treatment through electrochemical anodization. To prepare a stick junction, (2) photoactive TiO₂ nanoparticles were deposited over the porous layer by electrophoretic technique. Finally, (3) indium tin oxide (ITO) was sputtered. During the fabrication steps, we examined various anodization times ranging from 6 to 12 min to study the electrical behavior of the proposed device. Current–voltage measurements revealed higher performance for the 6 min sample, with a short circuit current density and open circuit voltage of 29.632 mA cm⁻² and 0.5 V, respectively. Also, morphology study showed uneven surface over the fabricated sample. Measurement of the optical properties showed potential anti-reflection surfaces. However, the 6 min sample, with an average reflectance of 1.9%, proved to be the competitive one. In addition, absorption data revealed a band gap of 1.38 eV for the 6 min sample, which is broader than that of others. Also, PL measurements explain the effective charge transfer for the lowest duration of anodization.