Cd-Free Wide Gap CuIn1-xGaxSe2 Solar Cells using Zn1-yMgyO Deposited by Pulsed Laser Deposition

Cd-free wide gap CuIn
_1-x
Ga
_x
Se
₂
(CIGS) solar cells were fabricated. Un-doped Zn
_1-y
Mg
_y
O (ZMO) and Al-doped Zn
_1-y
Mg
_y
O (AZMO) were used as window and transparent conducting (TC) layers, respectively. These layers were deposited by both RF-sputtering and pulsed laser deposition (PLD). While the Cd-free cells fabricated using RF-sputtering showed no solar cell response, these using PLD had solar cell properties. These results suggested that a sputtering process induced damage on CIGS absorber layer or on the interface between CIGS and window layer. Cd-free cells with ZMO window layer had the higher open circuit voltage V
_oc
than those with ZnO window layer. V
_oc
of Cd-free cells with AZMO TC layer was higher than that of AZO TC layer