Study On Preparation Of Sb₂S₃ Film Solar Cells By Spin-coating

Antimony sulfide(Sb2S3)film attracted much attention as an active layer in organic/inorganic hybrid solar cells because of the unique properties including a high absorption coefficient,intrinsic large dipole and band gap tuning.Sb2S3 has a variety of preparing methods.Chemical Bath Deposition method becomes the most widely used preparing method on account of large-scale production and low cost.However,the crystallization of the Sb2S3 thin films prepared by this method is poor.The introduction of water during the reaction process inevitably leads to the antimony oxide in the films,which makes the prepared thin films with a high density defect state.The defect state promotes the recombination of the carriers and suppresses the improvement of the device performance.In contrast,the crystallization of the Sb2S3 thin film prepared by the spin-coating method is good and the oxides of antimony is avoided as a result of no water in the preparation process.In this dissertation,we prepared Sb2S3 thin film with spin-coating method.Then the hybrid solar cells with a structure of FTO/TiO2/Sb2S3/P3HT/Al were prepared.We studied on the annealing,thickness and Ti doping of the Sb2S3 film to produce high power conversion efficiency(PCE)of the solar cells.The main research results obtained are as follows:1.We studied the optical and electrical properties of Sb2S3 films prepared by the spin coating.The Sb2S3 films were very smooth and uniform before and after annealed.The element ratio of the material was close to the ideal value of 2:3.There is no miscellaneous in the film and the crystallinity is very good.At the same time,the light absorption of the Sb2S3 film is strong.The absorption coefficient reaches 6.0 X 104 cm-1 and the band gap of the film is 1.68 eV.In addition,the carrier concentration and mobility of the Sb2S3 film is quite high,which are 1.192 ×1017cm-3 and 610 cm2/(Vs)respectively.2.We studied the effect of annealing temperature,annealing time,the thickness of the film on Sb2S3-based thin film solar cells.Sb2S3 film was found to initiate crystallize from 240 °C,crystallized at 280 °C.When the annealing temperature was 300 °C,the film morphology was the densest,the light absorption was the highest and PCE of the devices was also preferably 1.91%.The annealing time mainly affected the crystallinity and morphology of the film.It was found that when the annealing time was 10 min,the quality of the film was the best and the PCE of the solar cells was the highest.It was found that when the film thickness was 585 nm,the performance of the solar cell was the best.3.We studied the effect of Ti doping on Sb2S3 thin films and Sb2S3-based thin film solar cells.We found that Ti doping improved the film quality,reduced the surface state of the film,enhanced light absorption and greatly improved the performance of the solar cells.When the doping concentration was 6%,the optical properties of the film were optimal and PCE of the devices was also increased from 1.91%to 2.70%.The results above will lay a foundation for the preparation of the simple,low-cost,high-efficiency Sb2S3-based thin film solar cells.