Title :
Improvement of Cu(Ga,In)Se2 based solar cells by etching the absorber
Author :
Klenk, R. ; Menner, R. ; Cahen, D. ; Schock, H.
Author_Institution :
Inst. of Phys. Electron., Stuttgart Univ., Germany
Abstract :
The performance of the high-bandgap Cu(Ga,In)Se2-based solar cells is still limited by moderate fill factors and short-circuit currents due to incomplete carrier collection. A high recombination velocity at grain surfaces may be responsible for this behavior. In order to improve the performance, etching and passivating treatments with Br2-MeOH and KCN have been performed on Ga-rich absorbers, significantly increasing the fill factor and short-circuit current density. Fill factors of up to 56% were achieved for CuGaSe2/(Zn,Cd)S. The influence of the treatments on the absorber films was analyzed by various means. EDS analysis, scanning electron micrographs, and electrical measurements of conductivity and carrier density prove the removal of Cu2-xSe by KCN dip from Cu-rich films. In stoichiometric or Cu-poor films, no change can be seen by these methods
Keywords :
carrier density; copper compounds; electron-hole recombination; etching; gallium compounds; indium compounds; passivation; short-circuit currents; solar cells; ternary semiconductors; CuGaInSe2 solar cells; EDS analysis; absorber etching; carrier density; carrier density measurement; conductivity measurement; fill factors; grain surfaces; incomplete carrier collection; passivation; recombination velocity; scanning electron micrographs; short-circuit currents; Charge carrier density; Conductive films; Conductivity measurement; Current density; Density measurement; Electric variables measurement; Electrons; Etching; Photovoltaic cells; Surface treatment;
Conference_Titel :
Photovoltaic Specialists Conference, 1990., Conference Record of the Twenty First IEEE
Conference_Location :
Kissimmee, FL
DOI :
10.1109/PVSC.1990.111670
