TY - JOUR
T1 - Ultrafast pump-probe reflectance spectroscopy: Why sodium makes Cu(In,Ga)Se2 solar cells better
AU - Eid, Jessica
AU - Usman, Anwar
AU - Gereige, Issam
AU - Duren, Jeroen Van
AU - Lyssenko, Vadim
AU - Leo, Karl
AU - Mohammed, Omar F.
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2015/4/14
Y1 - 2015/4/14
N2 - Although Cu(In,Ga)Se2 (CIGS) solar cells have the highest efficiency of any thin-film solar cell, especially when sodium is incorporated, the fundamental device properties of ultrafast carrier transport and recombination in such cells remain not fully understood. Here, we explore the dynamics of charge carriers in CIGS absorber layers with varying concentrations of Na by femtosecond (fs) broadband pump-probe reflectance spectroscopy with 120 fs time resolution. By analyzing the time-resolved transient spectra in a different time domain, we show that a small amount of Na integrated by NaF deposition on top of sputtered Cu(In,Ga) prior to selenization forms CIGS, which induces slower recombination of the excited carriers. Here, we provide direct evidence for the elongation of carrier lifetimes by incorporating Na into CIGS.
AB - Although Cu(In,Ga)Se2 (CIGS) solar cells have the highest efficiency of any thin-film solar cell, especially when sodium is incorporated, the fundamental device properties of ultrafast carrier transport and recombination in such cells remain not fully understood. Here, we explore the dynamics of charge carriers in CIGS absorber layers with varying concentrations of Na by femtosecond (fs) broadband pump-probe reflectance spectroscopy with 120 fs time resolution. By analyzing the time-resolved transient spectra in a different time domain, we show that a small amount of Na integrated by NaF deposition on top of sputtered Cu(In,Ga) prior to selenization forms CIGS, which induces slower recombination of the excited carriers. Here, we provide direct evidence for the elongation of carrier lifetimes by incorporating Na into CIGS.
UR - http://hdl.handle.net/10754/575353
UR - http://linkinghub.elsevier.com/retrieve/pii/S092702481500152X
UR - http://www.scopus.com/inward/record.url?scp=84953923541&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2015.03.029
DO - 10.1016/j.solmat.2015.03.029
M3 - Article
SN - 0927-0248
VL - 140
SP - 33
EP - 37
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
ER -