Structural parameters of ZnO sol–gel thin-films after annealing at 400 °C.

	Layer	Thickness (nm)	ρ (Ω cm)	2θ	FWHM	D (nm)	a (Å)	c (Å)	a/c	L (Å)	σ (GPa)
N2	1 layer	95	0.065	34.43	0.64	13.2	3.24	5.21	0.62	2.60	−2.09
	3 layers	120	0.21	34.43	0.42	16.9	3.24	5.21	0.62	2.60	−1.37
	5 layers	420	0.3	34.43	0.5	16.9	3.24	5.21	0.62	2.60	−1.54
	6 layers	600	0.33	34.46	0.34	29.5	3.24	5.20	0.62	2.60	−0.94
Air	1 layer	95	0.051	34.44	0.31	27.3	3.24	5.21	0.62	2.60	−1.02
	3 layers	120	0.149	34.44	0.23	48.4	3.24	5.21	0.62	2.60	−0.58
	5 layers	420	0.267	34.45	0.23	35.9	3.24	5.20	0.62	2.60	−0.75
	6 layers	600	0.31	34.44	0.23	35.8	3.24	5.21	0.62	2.60	−0.75