| 摘要 |
Enhanced quality thin films of Cuw(In,Gay)Sez for semiconductor device applications are fabricated by initially forming a Cu-rich, phase-separated compound mixture comprising Cu(In,Ga):CuxSe on a substrate to form a large-grain precursor and then converting the excess CuxSe to Cu(In,Ga)Se2 by exposing it to an activity of In and/or Ga, either in vapor In and/or Ga form or in solid (In,Ga)ySez. Alternatively, the conversion can be made by sequential deposition of In and/or Ga and Se onto the phase-separated precursor. The conversion process is preferably performed in the temperature range of about 300 DEG -600 DEG C., where the Cu(In,Ga)Se2 remains solid, while the excess CuxSe is in a liquid flux. The characteristic of the resulting Cuw(In,Ga)ySez can be controlled by the temperature. Higher temperatures, such as 500 DEG -600 DEG C., result in a nearly stoichiometric Cu(In,Ga)Se2, whereas lower temperatures, such as 300 DEG -400 DEG C., result in a more Cu-poor compound, such as the Cuz(In,Ga)4Se7 phase. |
