표제지
요약
목차
I. 서론 13
II. 이론적 배경 16
1. 태양전지의 개요 16
1.1. 태양전지의 광전효과 16
1.2. 태양전지 특성 인자 21
2. 태양전지의 분류 24
3. CIGS 태양전지의 특성 25
3.1. CIGS 태양전지 연구의 필요성 25
3.2. CIGS의 물성 27
4. CIGS 태양전지 제조 31
4.1. CIGS 태양전지의 구조 31
4.2. CIGS 태양전지의 제조 공정 33
III. Mo 하부전극의 특성 35
1. 하부전극의 특성 35
2. Mo 물성 35
2.1. Mo 기본 물성 35
2.2. Mo 박막의 물성 36
2.3. MoSe₂ 박막의 영향 38
3. 스퍼트 이론 38
IV. 실험 및 평가 방법 43
1. 실험방법 43
1.1. 소다라임 유리의 플라즈마 전처리 45
1.2. Mo 박막의 제조 46
1.3. MoSe₂ 박막의 형성 50
1.4. Mo 박막의 플라즈마 후처리 52
1.5. CIGS 박막 태양전지 제조 52
2. 평가 방법 55
V. 결과 및 고찰 56
1. Mo 박막의 특성 56
1.1. 공정압력에 따른 특성 56
1.2. Mo 박막의 증착 두께 따른 특성 62
1.3. Mo 박막의 열처리 따른 특성 65
2. MoSe₂ 박막 특성 70
3. Mo 박막의 플라즈마 후처리 특성 74
4. CIGS 박막 태양전지의 특성 76
VI. 결론 79
참고문헌 82
Abstract 86
Table. 1. Basic properties of CIGS 29
Table. 2. Basic physical properties of molybdenum 37
Table. 3. Fabrication process of CIGS device 44
Table. 4. Experimental condition of plasma treatment for sodalime glass 45
Table. 5. Experimental condition of the Mo films deposited at different working pressures 48
Table. 6. Experimental Condition of the Mo films deposited at different deposition time 49
Table. 7. Experimental condition of the Mo films deposited at different thermal temperature 49
Table. 8. Experimental condition of the Se/CIG/Mo/SLG structure deposited 51
Table. 9. Plasma treatment condition for Mo flims 52
Table. 10. Fabrication condition of solar cell device 54
Table. 11. Analysis result of the Mo films as function of the thickness 63
Table. 12. Thickness data of the Mo films for selenization time at (a) 5min, (b) 20min, (c) 25min, (d) 40min 73
Table. 13. Mo films characteristics before plasma treatment 75
Table. 14. Mo films characteristics after plasma treatment 75
Fig. 1. Schematic of the photovoltaic effect, illustration how sunlight is converted to electricity via absorption, electron-hole pair generation, and separation 19
Fig. 2. Sketch of a p-n-junction including electron hole pair generation, thermalisation and recombination.The sketch shows a homojunction 19
Fig. 3. (a) Energy band gap of semiconductor p-n junction of equilibrium (b) Change of energy band gap by light illuminate 20
Fig. 4. I-V curve of photodiode by light illuminate 20
Fig. 5. Equivalent circuit of solar cell 23
Fig. 6. I-V characteristics of solar cell 23
Fig. 7. Classification of solar cell 24
Fig. 8. Comparison of Shell Solar Silicon and CIGS processes 26
Fig. 9. Unit cell of the tetragonal chalcopyrite structure of stoichiometric CuGaSe₂. and CuGaSe₂ 29
Fig. 10. Gibbs phase triangle of the ternary copper-indium-sulfur system at room temperature 30
Fig. 11. Pseudo-binary In₂Se₃-Cu₂Se phase diagram 30
Fig. 12. Absorption coefficients of CIS, CGS and CIGS.Very high absorption coefficients in the main solar spectrum(:~105cm-1)(이미지참조) 30
Fig. 13. CIGS device structure 32
Fig. 14. Cross-sectional view of the CIGS solar cell structure (not to scale) 32
Fig. 15. Monolithic structure of CIGS solar cell 32
Fig. 16. Production process for CIGS thin film solar cell based on sputtering process 34
Fig. 17. Fabrication process for CIGS thin film solar cell based on sputtering process 34
Fig. 18. A schematic diagram of a typical sputtering system 42
Fig. 19. Diagram for sputtering deposition process 42
Fig. 20. Structure of CIGS device 44
Fig. 21. In-line sputtering system for Mo deposition 48
Fig. 22. A typical Mo structure after high temperature selenization 51
Fig. 23. Sample image of CIGS solar cell 54
Fig. 24. Discharge current and discharge voltage characteristics of DC reactive magnetron sputtering 59
Fig. 25. Surface FESEM morphologies of the Mo films deposited at an Ar pressure of 1.3. mTorr(a), 4.9. mTorr(c) 59
Fig. 26. Cross sectional FESEM images of the Mo films deposited at an Ar pressure of 1.3. m Torr(a) and 4.9. mTorr(c) 60
Fig. 27. Thickness of Mo thin film deposited at (a) 1.3. mTorr, (b) 3.0mTorr, (c) 4.9. mTorr 60
Fig. 28. X-ray diffraction spectra of the Mo films grown at different working pressures 61
Fig. 29. Sheet resistance of Mo thin film deposited at (a) 1.3. mTorr, (b) 3.0mTorr, (c) 4.9. mTorr 61
Fig. 30. Electrical resistivity of Mo films as a function of the thickness 63
Fig. 31. Cross sectional FESEM images of the Mo films for gas working pressures at 1.3. mTorr (a) 0.63㎛, (b) 1.24. ㎛ 64
Fig. 32. Surface FESEM morphologies of the Mo films for gas working pressures at 1.3. mTorr (a) 0.63㎛, (b) 1.24. ㎛ 64
Fig. 33. X-ray diffraction spectra of the Mo films grown at different deposition temperature (a) RT, (b) 100℃, (c) 200℃ 66
Fig. 34. Surface FESEM morphologies of the Mo films for gas working pressures at (a) RT, (b) 100℃, (c) 200℃ 67
Fig. 35. Cross sectional FESEM images of the Mo films for deposition temperature at (a) RT, (b) 100℃, (c) 200℃ 68
Fig. 36. Thickness of Mo films as a function of the temperature 69
Fig. 37. Sheet resistance of Mo films as a function of the temperature 69
Fig. 38. FESEM image of CIGSe device cross-sections before selenizaition 72
Fig. 39. FESEM images of CIGSe thin film device cross-sections after selenizaition : (a) 5min, (b) 20min, (c) 25min, (d) 40min 72
Fig. 40. Thickness data of the MoSe₂ films for selenization time at (a) 5min, (b) 20min, (c) 25min, (d) 40min 73
Fig. 41. Sheet resistance and thickness after plasma treatment 75
Fig. 42. I-V Characteristics for CIGS solar cells with 1.2μm thickness Mo film 78
Fig. 43. I-V Characteristics for CIGS solar cells with 0.6μm thickness Mo film 78