학술논문

Rapid fabrication of Cu(In,Ga)Se2 thin films by the two-step selenization process
Document Type
Conference
Source
2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2 Photovoltaic Specialists Conference (PVSC), Volume 2, 2012 IEEE 38th. :1-7 Jun, 2012
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Photonics and Electrooptics
Power, Energy and Industry Applications
Metals
Surface morphology
Surface treatment
Grain size
Photovoltaic cells
Stacking
X-ray scattering
Copper indium gallium diselenide
Cu(In, Ga)Se2 (CIGS)
photovoltaic cells
selenization
thin films
Language
Abstract
Two-step processes currently used for the industrial Cu(In,Ga)Se 2 (CIGS) module production require a long process time of several hours for the CIGS absorber formation. In this paper, we are studying the reaction pathway to rapid selenization of stacked metal precursors in elemental Se vapor. The objective is to understand the reaction kinetics to find the best precursor structure and the optimal selenization conditions to form high-quality CIGS films with proper Ga depth profiles. In addition to stacked metal precursors, the effect of the use of Se-containing precursors was also examined. As expected, the stacking order of themetal precursors influences the properties of the resultingCIGS absorbers. The Cu amount deposited for the precursor formation critically affected the final film and cell properties, as well.We also found that the formation of CIGS films with large grain sizes and flat Ga depth profiles was possible even for [Cu]/([In] + [Ga]) < 1 conditions with the use of particular precursor structures and selenization conditions. The results suggest that the selenization reaction pathway can be dictated with the precursor structure, and further improvements are expected by controlling reaction kinetics with precursor structure modification.