Dependence of the Properties of Cu(In,Ga)S2/Mo Films Prepared by Two-Stage Evaporation Method on Degree of Vacuum during Deposition
The influence of background pressure in multisource evaporation is not straightforward to explain, but it is clear that the amount of absorbed gases on the surface of the growing grains change with pressure. This may influence surface energies, and consequently the growth mechanism. We investigated...
Saved in:
| Published in | Jpn J Appl Phys Vol. 51; no. 10; pp. 10NC17 - 10NC17-3 |
|---|---|
| Main Authors | , , , |
| Format | Journal Article |
| Language | English Japanese |
| Published |
The Japan Society of Applied Physics
25.10.2012
|
| Online Access | Get full text |
Cover
Loading…
| Summary: | The influence of background pressure in multisource evaporation is not straightforward to explain, but it is clear that the amount of absorbed gases on the surface of the growing grains change with pressure. This may influence surface energies, and consequently the growth mechanism. We investigated the relation between the orientation of Cu(In,Ga)S 2 films and pressure during deposition. We varied the background pressure during the deposition of the precursor film (first stage) by varying the temperature of the sulphur source, by throttling the vacuum pump, or by introducing N 2 gas. We found that Cu(In,Ga)S 2 films prepared from In--Ga--S precursors show (112) orientation if the pressure during precursor deposition is less than 0.03 Pa when the pressure is mainly attributable to sulphur. When it is mainly due to N 2 gas, the pressure at which the orientation changes is 0.14 Pa. The orientation of the final film reflects the orientation of the (In,Ga) 2 S 3 precursor immediately before entering the second stage. |
|---|---|
| Bibliography: | XRD patterns of Cu(In,Ga)S 2 films prepared from (In--Ga--S) precursor deposited at pressures of 0.018 Pa (a) and 0.055 Pa (b). The (112) splitting peak of (a) is due to the inhomogeneous incorporation of Ga. (204) XRD peak intensities of Cu(In,Ga)S 2 films normalized by the (112) intensity (a), and (112) and (204) intensities (raw intensities before removal of background) (b) as a function of pressure (mainly that of sulphur during precursor deposition). XRD patterns of (In--Ga--S) precursors deposited at 0.006 Pa (a) and 0.07 Pa (b) at 250 °C, and at 0.003 Pa (a$'$) and 0.06 Pa (b$'$) also deposited at 250 °C but then subsequently annealed at 580 °C for 20 min. (a) XRD patterns of (In,Ga) 2 S 3 precursor films deposited at 250 °C under different flow rates of N 2 gas [the $\text{S}/(\text{In}+\text{Ga})$ ratio was kept constant, the base pressure without N 2 was below 0.01 Pa], and then annealed at 580 °C for 20 min. (b) XRD patterns of Cu(In,Ga)S 2 films prepared from precursors shown in Fig. . (c) (204) XRD peak intensities of Cu(In,Ga)S 2 films normalized by the (112) intensity and (311) XRD peak intensities of (In,Ga) 2 S 3 films normalized by the (111) intensity, as a function of pressure (mainly N 2 partial pressure). |
| ISSN: | 0021-4922 1347-4065 |
| DOI: | 10.1143/JJAP.51.10NC17 |