Thin film solar cell and method of fabricating the same

Patent metadata

Field	Value
Publication number	US-10014431-B2
Application number	US-201615139479-A
Country	US
Kind code	B2
Filing date	Apr 27, 2016
Priority date	Aug 22, 2013
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

Disclosed is a thin film solar cell including a substrate, a first electrode, a light absorbing layer, a buffer layer, a window layer, and a second electrode, wherein a compound layer of M x S y or M x Se y (here, M is metal, and x and y each are a natural number) is present in an interface between the first electrode and the light absorbing layer, the thickness of the compound layer of M x S y or M x Se y being 150 nm or less.

First claim

What is claimed is:

1. A method for manufacturing a CZTS-based thin film solar cell, the method comprising:
preparing a substrate including Na and O (S 1 );
forming a first electrode on the substrate (S 2 );
pre-heat-treating the first electrode at a temperature of ⅓*Tm to ½*Tm based on the melting temperature (Tm) of the first electrode (S 3 ), such that Na and O from the substrate diffuses into the first electrode;
depositing a metallic precursor including Zn, Sn, Cu and S on the pre-heat-treated first electrode (S 4 ); and
heat-treating the deposited metallic precursor layer under sulfurization or selenization gas atmosphere, to form a light absorbing layer (S 5 ), such that Na and O diffusing to the first electrode further diffuses into a grain boundary in the light absorbing layer, a compound layer of MxSy or MxSey (here, M is metal, and x and y each are a natural number) is formed in an interface between the first electrode and the light absorbing layer, the thickness of the compound layer of MxSy or MxSey being 150 nm or less.

2. The method of claim 1 , wherein the first electrode is a molybdenum (Mo) thin film.

3. The method of claim 1 , wherein the temperature for the pre-heat treatment is 400-600° C.

4. The method of claim 1 , wherein the temperature for the pre-heat treatment is 500-600° C.

5. The method of claim 1 , wherein the pressure for the pre-heat treatment is 400-760 Torr.

6. The method of claim 1 , wherein in step S 4 , a CZT-based metallic precursor layer is formed by sequentially depositing a Zn precursor, a Sn precursor, and a Cu precursor on the first electrode.

7. The method of claim 1 , wherein the metallic precursor layer is formed by any one selected from sputtering, evaporation, chemical vapor deposition, metal organic chemical vapor deposition (MOCVD), close-spaced sublimation (CSS), spray pyrolysis, chemical spraying, screen printing, vacuum-free liquid-phase film deposition, chemical bath deposition (CBD), vapor transport deposition (VTD), and electrodeposition.

8. The method of claim 1 , further comprising:
forming a buffer layer on the light absorbing layer (S 6 );
forming a window layer on the buffer layer (S 7 ); and
forming a second electrode on the window layer (S 8 ).

Assignees

• Daegu Gyeongbuk Inst Science & Tech

Inventors

• Yang Kee Jeong
• Jeon Bo Ram
• Sim Jun Hyoung
• Son Dae Ho
• Kang Jin Kyu

Classifications

• C23C14/185

  by cathodic sputtering · CPC title

• Y02E10/541

  CuInSe2 material PV cells · CPC title

• C23C14/5866

  Treatment with sulfur, selenium or tellurium · CPC title

• C23C14/5806

  Thermal treatment · CPC title

• C23C14/34

  Sputtering · CPC title