| Metal chalcogenide compound semiconductors are important inorganic semiconductor materials, they are widely used in photocatalyst, solar cells, biosensors as well as photoconductors due to their special optical and electrical properties, and the synthesis of metal chalcogenide compound semiconductors is a hot point of recent researching. In this thesis, we ultilize solvothermal, hydrothermal and electrochemical deposition method to synthesis Cu2ZnSnS4(CZTS), ZnIn2S4 (ZIS), and SnS thin films, respectively, besides, the possible mechanisms of the formation of thin films on FTO substrates are also proposed. The contents of this paper are summarized as follows:1. The p-type Cu2ZnSnS4 (CZTS) nanoworm film with the band gap of 1.62eV have been directly deposited on fluorine-doped tin oxide (FTO) conductive glass substrates by a solvothermal method using polyethylene glycol 400 (PEG-400) as the solvent and structure-directing agent. The influence of the synthetic conditions on the properties of the thin films are investigated. The results show that with the increase of reaction temperature, the major diffraction peaks of CZTS thin films become narrower and sharper, indicating the improvement of the crystallinity of films, whereas, if the reaction temperature is to high(≥190℃), the impurity phase such as ZnS will be produced; Prolonging the reaction time is beneficial to improving the crystallinity of the films, however, if the reaction time is too long (>22h), the thin films will peel off from the FTO substrate. Furthermore, The p-type CZTS nanoworm film exhibits a power conversion efficiency of 1.18% by forming a photoelectrochemical cell.2. ZnIn2S4 thin films are successfully deposited onto FTO conductive glass substrates by a hydrothermal method using zinc chloride, indium chloride and thiourea (CH4N2S) as the starting materials, The influence of the synthetic conditions on the properties of the thin films are investigated. The results show that the reaction temperature have a great influence on the purity of the ZnImS4 thin films, when the reaction temperature is 140℃, the sample contained the the impurity phase (In(OH)3) and the binary products of ZnS will be formed at high temperature (>190℃), the thickness of the nanosheets seem to raised with the increase of reaction temperature, which is similar to the trend of the band gap. The intensity of PL is firstly decreased and then increased with the increase of reaction temperature, and the PL intensity obtained over the sample which synthesized at 160℃ is the weakest. The network structure and rice structure are obtained when using L-cysteine and thioacetamide as sulfur source, respectively. The carrier concentrations of thin films are firstly increased and then decreased with the increase of concentrations of precursor, and the sample which prepared with Co has the highest carrier concentration (6.70×1019cm-3).3. SnS thin films are successfully deposited onto FTO conductive glass substrates by the electrochemical deposition method using tin(II) chloride dihydrate and sodium thiosulphate as the starting materials, The influence of the synthetic conditions on the properties of thin films are investigated. The results show that the crystallinity, power conversion efficiency and grain size of the films are improved with the more negative of deposition potential(-0.7V,-0.8V,-0.9V,-1.0V), and the sample which synthesized at-1.0 V has the highest carrier concentration (5.7×1021 cm-3). The direct band gap of thin films which prepared at different deposition potential are in the range of 1.32-1.41eV, which are suitable for the thin film solar cells. The concentration ratio of Sn2+and S2O32- play a key role in the formation of SnS thin films, when the concentration ratio is 1:1, the product is the single Sn. |
PDF Full Text Request