Study On The Properties Of The Photovoltaic Materials-cuprous Oxide

Energy is the driving force of the social development, and fossil fuel energy is closely related tothe human life. As we all know, the pollution caused by the fossil fuels make human livingenvironment worse, and fossil fuel reserves gradually reduced, can not meet the long-term needs ofthe human developments. Solar energy is inexhaustible green energy. The development of solarenergy is one of the most effective way to solve the current problems of energy shortage andenvironment pollution.There are many materials, which can be used as solar cell materials, but they have their owndrawbacks. For example, high-purity silicon has disadvantages of high production costs and; forCIGS materials, the indium and selenium are rare elements; CdS and CdTe are highly toxic and veryharmful to the environment. So, the development of new solar cell materials is imperative. Cuprousoxide is a oxide semiconductor with abundant raw materials, direct band structure and theoreticaladvantages of higher conversion efficiency, which indicates that cuprous oxide is a promisingphotovoltaic materials.In this paper, electrochemical method was used to deposit the cuprous oxide thin film in athree-electrode electrochemical cell. By the control of solution pH, the conduction type of cuprousoxide was controlled. Annealing method was used to optimize the crystal orientation of cuprousoxide thin films, and the optical and electrical characterizations were performed: Main conclusionsare as follows:1. By controlling the deposition pH of the solution, the surface morphology and crystalorientation of cuprous oxide film were controlled successfully, and a reasonable explanation on themechanism was also given. It is found that, as pH value was7.5or less, the crystal morphology ofcuprous oxide thin films was4-sided pyramid; as pH value was about10.0, the crystal morphologyof cuprous oxide thin films were triangular prisms and as pH value was about12.0, cuprous oxidethin films had a three-sided pyramid surface morphology. As pH value was below7.5, theconduction type of cuprous oxide thin film was n-type, while as pH value was above9.0, the conduction type was p-type. It was also determined that the cuprous oxide film has a direct bandstructure with a band gap of2.06eV.2. By comparing the XRD patterns for samples before and after annealing at200°C,250°C,300°C,350°C,400°C, it was found that with increasing annealing temperature, the crystalcrystallinity was highly improved. All of the above showed that heat treatment temperature was avery important factor on the crystal quality.