Photovoltaic device based on Ag
Photovoltaic devices based on an Ag 2 ZnSn(S,Se) 4 (AZTSSe) absorber and techniques for formation thereof are provided. In one aspect, a method for forming a photovoltaic device includes the steps of: coating a substrate with a conductive layer; contacting the substrate with an Ag source, a Zn source, a Sn source, and at least one of a S source and a Se source under conditions sufficient to form an absorber layer on the conductive layer having Ag, Zn, Sn, and at least one of S and Se; and annealing the absorber layer. Methods of doping the AZTSSe are provided. A photovoltaic device is also provided.
1. A method for forming a photovoltaic device, the method comprising the steps of:
coating a substrate with a conductive layer;
contacting the substrate with an Ag source, a Zn source, a Sn source, and at least one of a S source and a Se source under conditions sufficient to form an absorber layer on the conductive layer comprising Ag, Zn, Sn, and at least one of S and Se; and
annealing the absorber layer,
wherein the method further comprises the step of:
forming a Na-containing layer on the substrate prior to performing the contacting step.
2. The method of claim 1 , wherein the conditions comprise: a temperature, a duration, and a pressure.
3. The method of claim 2 , wherein the temperature is from about 10° C. to about 450° C., and ranges therebetween.
4. The method of claim 2 , wherein the duration is from about 1 minute to about 200 minutes, and ranges therebetween.
5. The method of claim 2 , wherein the pressure is from about 1×10 −5 Torr to about 5×10 −10 Torr, and ranges therebetween.
6. The method of claim 1 , wherein the substrate comprises a glass, a ceramic, a metal foil, or a plastic substrate.
7. The method of claim 1 , wherein the conductive layer comprises a material selected from the group consisting of: a metal-containing material, a transparent conducting oxide, and combinations thereof.
8. The method of claim 1 , further comprising the step of:
coevaporating the Ag source, the Zn source, the Sn source, and the at least one of the S source and the Se source.
9. The method of claim 1 , further comprising the step of:
producing a regulated amount of the S source and the Se source using a S cracking cell and an Se cracking cell.
10. The method of claim 1 , wherein the Na-containing layer comprises NaF, Na 2 S or Na 2 Se.
11. The method of claim 1 , further comprising the step of:
doping the absorber layer.
12. The method of claim 11 , wherein the absorber layer is doped with a metal selected from the group consisting of: In, Ga, and combinations thereof.
13. The method of claim 12 , wherein the absorber layer is doped with a halide selected from the group consisting of: Cl, Fl, I, Br, and combinations thereof.
14. The method of claim 1 , wherein the annealing is performed at a temperature of from about 430° C. to about 550° C., and ranges therebetween.
15. The method of claim 1 , further comprising the step of:
forming a buffer layer on the absorber layer.
16. The method of claim 15 , wherein the buffer layer comprises a material selected from the group consisting of: Cu 2 O, NiO, ZnTe, AlP, CdTe, Cul, MoO 3 , MoO 2 , MoS 2 , MoSe 2 , and combinations thereof.
17. The method of claim 15 , further comprising the step of:
forming a transparent front contact on the buffer layer.