The Preparation And Optical Band Gap Of Cigs Thin Films And Cds Thin Films

With adjusting the deposition pressure and heat treatment temperature, The CIGS thin film absorption layer and CdS thin film buffer layer were prepared on glass substrates by pulsed laser deposition (PLD), respectively. The crystal structure was determined by X ray diffraction (XRD). The light absorption characteristic was analyzed by UV-visible spectrophotometer. Through the optimization of CIGS film and CdS film preparation process, the better CIGS thin film absorption layer and CdS thin film buffer layer preparation processes were found.The experimental results showed that the better CIGS thin film absorption layer was prepared by PLD and after heat treatment. The thin film had a good light absorption characteristic. Along with the rise of heat treatment temperature, the average grain size was gradually increased. Along with the rise of deposition pressure, the (112) diffraction relative intensity of CIGS film was increased. Especially when the deposition pressure was1Pa, the (112) diffraction relative intensity was maximum, and the thin film along the<112> orientation was preferential grown. Along with the rise of deposition pressure, the transmission of thin film was slightly enhanced and band gap was about1.12-1.19eV, but the absorption limit changed little.The experimental results also showed that the six phase CdS polycrystalline structure was prepared by PLD and after heat treatment (350degrees C,20min, Ar atmosphere). The CdS film along the <002> orientation was preferential grown. The transmission rate of CdS thin film was very high (70%-98%) in the visible region and even in the near infrared region. Especially when the deposition pressure was lOPa, the maximum transmission rate can reached92%or above in550-900nm region. Along with the rise of deposition pressure, the average grain size was gradually increased, and the optical band gap was gradually increased, too.