Fabrication of CuIn1-xGaxSe2 Thin Film Solar Cells using Molecular Beam Epitaxy System

Abstract

The CuIn1-xGaxSe2 polycrystalline thin films were fabricated using the molecular beam epitaxy(MBE) system. The in situ monitoring technique was employed for process control and end-point detection(EPD). Two temperature profiles; the two-stage and the three-stage processes were performed in thegrowth process. From the current-voltage (I-V) measurement, the CuIn1-xGaxSe2 thin film solar cells,fabricated with the two-stage process yielded efficiencies 11% (x~0.3) and the efficiencies decrease forwide band gap CuIn1-xGaxSe2 (x>0.5) films. The CuIn1-xGaxSe2 thin film solar cells fabricated using thethree-stage process, showed the efficiency up to 15.3% (x~0.3). The cell performance of the wide bandgap CuIn1-xGaxSe2 (x>0.5) solar cells is also improved by the three-stage process.

Keywords : Solar Cell / Polycrystalline / Thin Film / Efficiency / Temperature Profile