Abstract:
The demand for low cost, high efficiency solar cells is the power of thin film solar cells.
In recent years, antimony sulfide (Sb2S3) has much attraction as light harvesting material
in solar cell applications. Sb2S3 solar cells are reported with a dense blocking layer and
mesoscopic TiO2 scaffold. But still, in both cases, the performance of Sb2S3 solar cells are
unsatisfactory. However, planner Sb2S3 solar cells would be more competitive because it
is simpler and has a higher open circuit voltage due to reduced charge carrier
recombination. Herein, planner Sb2S3 solar cells have been successfully made using spin
coated Sb2S3 as the absorber, dense blocking TiO2 (bl-TiO2) as the electron conductor and
poly (3-hexathiophene) (P3HT) as the hole conductor. This study pinpointed the
dependence of cell performance on the thickness of the blocking TiO2 layer. The bl-TiO2
was deposited by spin coating at rpm with a different number of spin coat cycles (1-5).
The TiO2 precursor solution was prepared by mixing of Titanium IsoPropoxide (TTIP), of
butol-1-ol and of diethanolamine. The blocking properties and thickness variation of the
bl-TiO2 layers fabricated with a various number of spinning cycles were verified by cyclic
voltammograms and UV-Vis spectra respectively. The optimization of the TiO2 blocking
layer to enhance the device performance was carried out on the planner device consisting
of FTO/bl-TiO2/Sb2S3/P3HT/Ag and the optimized device with of bl-TiO2 exhibited the
power conversion efficiency of at 1 sun illumination.
Keywords: Blocking TiO2, Planner structure, Performance, Sb2S3, and Spin coat cycle
