Investigation Of ZnO Nanorod And Counter Electrode Materials Based On Quantum Dot Sensitized Solar Cells

Quantum dot sensitized solar cells(QDSSCs)are considered to be promising photoelectric conversion devices because of their advantages of simple preparation,low cost,high theoretical conversion efficiency.The vertically aligned one-dimensional ZnO nanorods(NRs)can provide direct electron transport,which is conducive to the transfer of electrons.When they are applied to QDSSCs,it is expected to further improve the PCE of QDSSCs.The main work of this paper is as follows:(1)ZnO NRs were prepared on the surface of FTO transparent conductive substrates,and different lengths of ZnO NRs were obtained by changing the growth time of ZnO NRs.At the same time,CdS/CdSe/ZnO NRs with different lengths were used as the photoanodes of QDSSCs.(2)Copper sulfide/copper selenide were prepared on the surface of FTO transparent conductive substrate by microwave assisted vapor deposition.Then they were used as counter electrode of QDSSCs.The main research results are as follows:1.Water-bath method was used to prepare ZnO NRs on the surface of FTO transparent conductive substrates,and different lengths of NRs were obtained by changing the growth time of ZnO NRs.The morphology of ZnO NRs with different growth lengths and the effect of CdS/CdSe co-sensitized ZnO NRs as photoanodes on the PCE of QDSSCs were systematically investigated.As a result,ZnO NRs with the growth time of 2 h(5.4 ?m)had the best electron transfer ability.At the same time,CdS(6 times)and CdSe(4 h)deposited on the Zn O NRs(2 h)by successive ionic layer adsorption and reaction and chemical bath deposition on the PCE of QDSSCs were also investigated.It was confirmed that the CdS / CdSe co-sensitized ZnO NRs had the best performance when the deposition times were 6 and the deposition time was 2 h.Under one-sun illumination,the QDSSC assembled with CdS(6 times)/ CdSe(4 h)/ ZnO(5.4 ?m)and Pt counter electrode reached the PCE as high as 2.33%.2.Copper sulfide/copper selenide films were prepared on the surface of FTO transparent conductive substrate by microwave assisted vapor deposition.By changing the deposition time of copper sulfide in the reaction solution,different thickness of copper sulfide films were obtained.These nanoplates on the FTO substrate intercross with each other along the diameter direction,and increased the specific surface area of the membrane,thereby increasing the contact area of the electrolyte and the counter electrode.Similarly,CdS(6 times)/ CdSe(4 h)co-sensitized Zn O(2 h)NRs were used as photoanodes and copper sulfide was prepared as the counter electrode.Under one-sun illumination,the obtained PCE of QDSSCs was 4.46%,while QDSSCs with Pt counter electrodes just showed a conversion efficiency of 2.33%.In addition,we also systematically studied a series of properties of copper selenide as a counter electrode,and finally obtained a PCE of 2.07%.