Thermal treatment optimization of ZnO nanoparticles-photoelectrodes for high photovoltaic performance of dye-sensitized solar cells

Peer review under responsibility of University of Bahrain.

Figures & data

Figure 1 XRD pattern of the ZnO layer deposited on K-glass and sintered at 400 °C. The peaks refer to the Wurtzite hexagonal structure in the reference data (JCPDS No. 0036–1451).

Figure 2 SEM surface images of ZnO nanoparticles annealed at 100 °C (a), 200 °C (b), 300 °C (c) and 400 °C (d).

Figure 3 DTA/TG thermal analysis of a ZnO paste, heating rate 2 K/min in synthetic air.

Figure 4 UV–VIS absorbance of dye de-adsorped from ZnO photoelectrodes annealed at different temperatures.

Table 1 ZnO–DSSC performance with photoelectrodes annealed at different temperatures.

Temperature (°C)	Voc (mv)	Isc (mA/cm^2)	Efficiency (%)	FF
200	545	4.42	1.07	0.44419
300	544	12.51	2.02	0.29682
350	550	12.87	2.38	0.33623
400	552	15.66	3.01	0.34821
450	554	13.38	2.26	0.30489
500	573	8.64	1.47	0.29693

Figure 5 Adsorption–desorption isotherm using N2 at 77 K (a) and surface area (BET) (b) for ZnO nanoparticles annealed at different temperatures.

Figure 6 Current–Voltage characteristics of ZnO–DSSCs using ZnO nanoparticles photoelectrodes annealed at different temperatures.

Figure 7 Nyquist plots of ZnO-DSSCs using photoelectrode annealed at different temperatures (250 °C, 350 °C and 500 °C) with equivalent circuit model used in curve fitting.