Near-interface doping by ion implantation in Cu(In,Ga)Se2 solar cells

• Published in: Thin solid films Vol. 519; no. 21; pp. 7276 - 7279
• Main Authors: HAARSTRICH, J, METZNER, H, RONNING, C, RISSOM, T, KAUFMANN, C. A, SCHOCK, H. W, MANNSTADT, W, RUDIGIER-VOIGT, E, SCHEUMANN, V
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier 31-08-2011
• Subjects: Applied sciences; Cadmium; Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; Diffusion; interface formation; Dopants; Doping; Doping and impurity implantation in other materials; Energy; Exact sciences and technology; Ion implantation; Natural energy; Photovoltaic cells; Photovoltaic conversion; Physics; Simulation; Solar cells; Solar cells. Photoelectrochemical cells; Solar energy; Solid surfaces and solid-solid interfaces; Structure of solids and liquids; crystallography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin films; Solar cells; Buffer layer; Cadmium; Thermal diffusion; Gallium; Ion implantation; Annealing; Digital simulation; Doping; Doping profiles; Secondary ion mass spectrometry; Quantum yield; Cadmium sulfide; Cd diffusion; Interfaces; Experimental result; Thin film devices; EQE; Thin-film solar cells; Cu(In,Ga)Se; Surface inversion; Copper; Diffusion; Thermal annealing
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2010.12.090

Cu(In,Ga)Se2 absorber layers were implanted with 20keV Cd ions in order to investigate the influence of changes in the near-interface doping profile. Modifications in this region are shown by AMPS-1D simulations to have substantial impact on solar cell properties. Ion implantation and subsequent thermal annealing steps were monitored by SIMS measurements to control the thermal diffusion of the dopant. Solar cells both with and without CdS buffer layer were made from the implanted absorbers and characterized by j-V and EQE measurements. These experimental results in conjunction with simulations of the quantum efficiency show that a well-defined type-inversion of the implanted layer can be achieved by low-energy ion implantation.