The science describing semiconductor−liquid interfaces is highly interdisciplinary, broad in scope, interesting, and of importance to various emerging technologies. We present a review of the basic physicochemical principles of semiconductor−liquid interfaces, including their historical development, and describe the major technological applications that are based on these scientific principles.

Physical Chemistry of Semiconductor−Liquid Interfaces

Efficient solar energy conversion with CuInS2 thin films is reported. The copper‐rich p‐type absorber is prepared by thermal coevaporation. A copper to indium ratio between 1.0 and 1.8 can be tolerated with small (≤10%) solar‐to‐electrical conversion losses. Copper excess phases (CuS) are removed chemically. The cell structure glass/Mo/p‐CuInS2/n‐CdS/n+‐ZnO/Al delivers 10.2% at simulated AM 1.5 conditions. The device properties are discussed based on its energy band diagram.

CuInS2 based thin film solar cell with 10.2% efficiency

Solar cells based on CuInS2—an overview

An 11.4% efficient polycrystalline thin film solar cell based on CuInS2 with a Cd-free buffer layer

Microwave-assisted synthesis and photovoltaic measurements of CuInS2 nanoparticles prepared by using metal–organic precursors

The high absorptivity associated with a direct energy gap in the optimum range for solar-energy conversion makes CuInS2 a particularly promising material for efficient solar-energy conversion1. Achieved solar-to-electrical conversion efficiencies have been limited to ∼6% (refs 2–8). We report here a new heterogeneous poly crystalline n-CuInS2 based semiconductor which has yielded conversion efficiencies of 9.7% in an electrochemical cell. The high photoactivity is also evident in a Schottky barrier solar cell configuration. The origin of the improved efficiency is attributed to impurity scavenging by In spheres resulting from a modified vapour/liquid/solid (VLS) growth process9–11 and the influence of the acidic iodine iodide electrolyte on the cell performances.

Efficient solar energy conversion with CuInS2

The difference in photoactivity between CuInS2 crystals grown by chemical vapour transport (CVT) and new heterogeneous material containing phases of Cu2−xS and In2S3 in the mol % range is analysed. Photoluminescence, time resolved microwave conductivity (TRMC) experiments and photocurrent spectroscopy demonstrate a strongly reduced defect density in the heterogeneous samples. EBIC analyses show the terraces occurring from vapour-liquid-solid (VLS) growth of the heterogeneous material to act as recombination sites.

S. Fiechter

Papers

Efficient solar energy conversion with CuInS2

Electronic defects in heterogeneous CuInS2