Tuning donor-acceptor and free-bound transitions in CuInSe2/indium tin oxide heterostructure.

Infrared photoluminescence (PL) emissions centered at 1550 and 1564 nm were obtained at 15 K from CuInSe₂/indium tin oxide heterostructure. PL studies revealed transitions between donor-acceptor pairs and band to acceptor to be the origin of the 1550 and 1564 nm emissions, respectively. At low temperatures (15–60 K) the 1550 nm emission was prominent. Upon increasing the excitation intensity at low temperature the 1564 nm emission gained prominence. Increase in temperature also caused the 1564 nm emission to gain significance. The possibility of selecting one of the two emissions by adjusting temperature or excitation intensity is discussed. [ABSTRACT FROM AUTHOR]