13:30 〜 15:30
[6p-PA5-5] CuInS2 film growth on glass substrate by PLD method
キーワード：PLD method., solar cells
The ternary semiconductor CuInS2 is a promising photovoltaic base material for solar cells because of its optimum band-gap energy of 1.53 eV and large absorption coefficient above the band gap energy. Until now, conversion efficiency of 11.4% has been achieved for CuInS2 solar cells. However, the chalcopyrite Cu-III-VI2 solar cells show a theoretical photoelectric conversion efficiency of 27 to 32%. Therefore, high quality CuInS2 films are required to improve the actual performance of the CuInS2 solar cells. Moreover, excitonic emissions that are related to the high-quality nature of the films have rarely been observed.
The pulse laser deposition (PLD) method is receiving much attention for film deposition because: (1) it is possible to deposit films of despite a high melting point of the material via absorption of laser light by the material, (2) unlike other physical vapor deposition methods, a high degree of vacuum is not required, and (3) compositional mismatch between the target and the deposited film is small and easy to control.
We have previously reported a high quality CuInS2 film by the PLD method. However, one drawback of the film is its sulphur-poor composition, which induces sulfur vacancies into the films leading to shallow donors. In the present work, CuInS2 thin films were deposited on glass substrates by PLD using a compositionally controlled target. To minimize the deviation of the compositional ratio between the target and the film, the target was constructed with CuInS2 poly-crystal and In2S3 and S powders to adjust the compositional ratio.
X-ray diffraction (XRD) and photoluminescence (PL) measurement results reveal that the obtained films have good quality crystalline chalcopyrite structure. Moreover, the PL spectra showed free- and bound-excitonic emissions over large areas of the films, as observed using a confocal microscopy system.
The pulse laser deposition (PLD) method is receiving much attention for film deposition because: (1) it is possible to deposit films of despite a high melting point of the material via absorption of laser light by the material, (2) unlike other physical vapor deposition methods, a high degree of vacuum is not required, and (3) compositional mismatch between the target and the deposited film is small and easy to control.
We have previously reported a high quality CuInS2 film by the PLD method. However, one drawback of the film is its sulphur-poor composition, which induces sulfur vacancies into the films leading to shallow donors. In the present work, CuInS2 thin films were deposited on glass substrates by PLD using a compositionally controlled target. To minimize the deviation of the compositional ratio between the target and the film, the target was constructed with CuInS2 poly-crystal and In2S3 and S powders to adjust the compositional ratio.
X-ray diffraction (XRD) and photoluminescence (PL) measurement results reveal that the obtained films have good quality crystalline chalcopyrite structure. Moreover, the PL spectra showed free- and bound-excitonic emissions over large areas of the films, as observed using a confocal microscopy system.