Non-Toxic Buffer Layers in Flexible Cu(In,Ga)Se₂ Photovoltaic Cell Applications with Optimized Absorber Thickness

Table 1

Material parameters for CIGS solar cell simulation.

Parameters	ZnO : Al	i-ZnO	CdS	CIGS
Thickness, τ (μm)	0.2	0.02	0.05	1
Dielectric constant, Eps	7.8	7.8	12	13.6
Refractive index, Ndx	2	2	3.15	3.67
Band gap, Eg (eV)	3.30	3.30	2.42	1.25
Electron affinity, χe (eV)	4.6	4.6	3.74	4.19
Donor concentration, Nd (cm^−3)	5 × 10^16	1 × 10^17	3 × 10^16	0
Acceptor concentration, Na (cm^−3)	0	0	0	2 × 10^16
Electron mobility, μn (cm^2 V^−1 s^−1)	100	100	120	110
Hole mobility, μp (cm^2 V^−1 s^−1)	25	25	40	35
Conduction band effective density of states, Nc (cm^−3)	2.2 × 10^18	2.2 × 10^18	2.2 × 10^18	2.2 × 10^18
Valence band effective density of states, Nv (cm^−3)	1.8 × 10^19	1.8 × 10^19	1.8 × 10^19	1.8 × 10^19