The influence of gallium on phase transitions during the crystallisation of thin film absorber materials Cu(In,Ga)(S,Se) 2 investigated by in-situ X-ray diffraction

• Published in: Thin solid films Vol. 519; no. 21; pp. 7197 - 7200
• Main Authors: Hölzing, A., Schurr, R., Jost, S., Palm, J., Deseler, K., Wellmann, P., Hock, R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 31-08-2011; Elsevier
• Subjects: Annealing; ANNEALING PROCESSES; Applied sciences; Chalcogenisation; CHALCOPYRITE; Cross-disciplinary physics: materials science; rheology; Crystallization; Cu(In,Ga)(S,Se) 2; Deposition by sputtering; Diffraction; Energy; Exact sciences and technology; Formation reaction; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Natural energy; Phase transformations; PHASES; Photovoltaic conversion; Physics; Precursors; SEMICONDUCTORS; SOLAR CELLS; Solar cells. Photoelectrochemical cells; Solar energy; Sulfoselenisation; THIN FILMS; X RAY DIFFRACTION; X RAYS; Sulfoselenisation; Cu(In,Ga)(S,Se) 2; Formation reaction; Chalcopyrite; Chalcogenisation; Polyimide; Crystalline phase; Gallium; Annealing; Semiconductor materials; Evaporation; X ray diffraction; Molybdenum; Precursor; Phase transitions; Thin film; Photovoltaic cell; Cu(In,Ga)(S,Se); Energy gap; Physical vapor deposition; Cathodic sputtering; Copper
• DOI: 10.1016/j.tsf.2010.12.138
• EISSN: 1879-2731
• ISSN: 0040-6090

Chalcopyrite based photovoltaic materials Cu(In
xGa
1
−
x
)(S
ySe
1
−
y
)
2 (CIGSSe) are substituted in the cation and anion lattice to adopt the semiconductor bandgap to the terrestrial solar spectrum. In-situ X-ray diffraction (XRD) investigations on the crystallisation of thin film absorber materials Cu(In,Ga)(S,Se)
2 while annealing stacked elemental layers (SEL) show phase transitions proceeding during the chalcopyrite synthesis.
Thin layers of metals with elemental ratio Cu:In:Ga
=
3:2:1 are deposited onto Mo-coated polyimide foil by DC-magnetron sputtering. The metal precursor is covered with S and subsequently Se by thermal evaporation of the elements in chalcogen excess (S
+
Se)
/
(Cu
+
In
+
Ga)
=
2.3. Investigated chalcogen ratios reach from pure Se to pure S. Crystalline phases formed during the annealing of SEL are qualitatively determined. The results are compared to conclusions drawn from previous experiments on Ga-free CuIn(S,Se)
2 absorbers. The presence of Ga and S influences significantly the time-scale and the temperatures of phase transitions, i.e. the sulfoselenisation of precursor phases Cu
16(In,Ga)
9 and Cu
9(Ga,In)
4 proceeds faster with increasing S and is shifted to higher temperatures as compared to Ga-free Cu
11In
9/Cu
16In
9.