ABSTRACT
This chapter demonstrates the gradual development seen during the two years in attaining high efficiency using graded bandgap configuration. Photovoltaic devices are developed mainly based on p–nor p–i–n-type device structures, and these devices can utilise only fraction of the solar spectrum. Graded bandgap devices produced using only two or three electroplated semiconductor layers have been explored, and their conversion efficiencies have gradually increased from 10.0%, through 12.8% to 15.3% for different structures. After experimentally testing the new concept of graded bandgap devices, work has begun to produce these devices using low-cost and scalable electroplated materials. Electrodeposition of semiconductors, which was first introduced by Panicker et al., can be achieved using either a 3-electrode (3E) or 2-electrode (2E) configuration, a suitable electrolyte containing the required precursors, a potentiostat, a stirrer and a hot plate. The utilisation of the electrodeposition technique under both 3E and 2E configuration show promises in the fabrication of high-efficiency solar cells using graded bandgap multi-layer device configuration.
