표제지
국문초록
목차
I. 서론 16
II. 이론적 배경 19
1. 양자점 19
2. 태양전지 21
2.1. 태양전지의 원리 21
2.2. 태양전지의 종류 24
3. 염료감응 태양전지 28
3.1. 염료감응 태양전지의 원리 28
3.2. 염료감응 태양전지의 구성 30
4. 졸-겔 반응 34
III. 실험장치 및 방법 36
1. 시약 및 시료 36
1.1. 양자점 온도센서 36
1.2. 염료감응 태양전지 37
1.3. 양자점감응 태양전지 37
2. 분석기기 38
2.1. 양자점 온도센서 38
2.2. 염료감응 태양전지 38
2.3. 양자점감응 태양전지 39
3. 양자점 온도센서의 제조 40
4. Nb2O5 sol의 합성(이미지참조) 42
5. 전자차단층을 도입한 염료감응 태양전지의 제조 44
5.1. Electron blocking layer on FTO 44
5.2. Electron blocking layer on TiO₂ 44
5.3. Electron blocking layer inside of TiO₂ 45
5.4. Electron blocking layer on FTO and inside of TiO₂ 45
6. 전자차단층을 도입한 양자점감응 태양전지의 제조 47
IV. 결과 및 토의 49
1. 양자점 온도센서 49
1.1. Fluorescence microscopy 분석 49
1.2. Photoluminescence spectroscopy 분석 51
2. Nb2O5 전자차단층의 특성 분석(이미지참조) 60
3. 전자차단층을 도입한 염료감응 태양전지의 특성 분석 66
3.1. Electron blocking layer on FTO 67
3.2. Electron blocking layer on TiO₂ 72
3.3. Electron blocking layer inside of TiO₂ 76
3.4. Electron blocking layer on FTO and inside of TiO₂ 83
4. 전자차단층을 도입한 양자점감응 태양전지의 특성 분석 87
4.1. 양자점을 고정한 일전극의 특성 분석 87
4.2. 양자점감응 태양전지의 전기적 특성 분석 102
V. 결론 106
VI. 참고문헌 108
ABSTRACT 113
Table I. The performance values of DSSCs with blocking layer on FTO. 71
Table II. The performance values of DSSCs with blocking layer on TiO₂. 75
Table III. SEM-EDX data of Nb2O5·TiO₂ paste.(이미지참조) 78
Table IV. The performance values of DSSCs with blocking layer inside of TiO₂. 82
Table V. The performance values of DSSCs with blocking layer on FTO and inside of TiO₂. 86
Table VI. EDX properties QDs immobilized working electrode of FIB/SEM. 101
Table VII. The performance values of QDSSCs using different linker molecule. 103
Table VIII. The performance values of QDSSCs using different electrolyte. 104
Table IX. The performance values of QDSSCs with blocking layer. 105
Figure 1. Density of states in 3, 2, 1 and 0 dimension. 20
Figure 2. (a) The structure of conventional Si solar cell. (b) Energy band diagram of conventional Si solar cell. 22
Figure 3. (a) The spectra of the sun. (b) the theory of Airmass. 23
Figure 4. Categorization of solar cell. 25
Figure 5. Efficiency versus cost for the three generations of solar cells. 26
Figure 6. The best research cell efficiencies records. 27
Figure 7. Energy level diagram of a conventional dye-sensitized solar cell. 29
Figure 8. Overview of sol-gel process. 35
Figure 9. The system for tapering optical fiber by wet etching and shape change of the fiber tip. 41
Figure 10. Preparation of Nb2O5 sol.(이미지참조) 43
Figure 11. Preparation of DSSCs with different types of electron blocking layer. 46
Figure 12. Preparation of QDSSCs with Nb2O5 blocking layer.(이미지참조) 48
Figure 13. Scheme of immobilization of QDs. 49
Figure 14. Fluorescence microscopy images of QDs immobilized optical fiber (a) under white-light and (b) UV light. 50
Figure 15. Experimental setup for temperature control and PL analysis on QDs immobilized optical fiber. 52
Figure 16. The PL spectra of QDs in ambient air and in oil bath. λex = 450 ㎚(이미지참조) 53
Figure 17. PL spectra of optical fiber temperature sensor with (a) Green QDs (525 ㎚), (b) Orange QDs (605 ㎚), and (c) Red QDs (705㎚). 55
Figure 18. The PL intensity variation with temperatures at fixed wavelength: green QDs at 520 ㎚, orange QDs at 600㎚, and red QDs at 700㎚. 56
Figure 19. The emission-peak wavelength variation of QDs with temperature 58
Figure 20. The cyclic behavior of PL intensity of QDs 59
Figure 21. Sol-gel process of Nb2O5.(이미지참조) 61
Figure 22. The scheme of Nb2O5 electron blocking layer.(이미지참조) 62
Figure 23. Photograph images of Nb2O5 sol with different molar ratio.(이미지참조) 63
Figure 24. The XRD data of Nb2O5 thin film.(이미지참조) 64
Figure 25. SEM images of Nb2O5 thin film aftet sintered at 600℃ for 2hr.. the molar ratio of niobium ethoxide:H₂O= (a) 1:1, (b) 1:2, (c) 1:3, (d) 1:4. 65
Figure 26. The structure of DSSCs with different blocking layer. blocking layer was placed (a) on FTO, (b) on TiO₂, (c) inside of TiO₂, (d) on FTO and inside of TiO₂. 66
Figure 27. SEM image of the surface of TiO₂ layer. 68
Figure 28. FIB/SEM images of working electrode. The electron blocking layer was placed on FTO glass. 69
Figure 29. The cross-sectional FIB/SEM image of DSSCs with Nb2O5 layer (a) with EDX mapping(이미지참조) 70
Figure 30. J-V curve of DSSC with blocking layer on FTO. 71
Figure 31. FIB/SEM images of working electrode. The electron blocking layer was placed on TiO₂. 73
Figure 32. The cross-sectional FIB/SEM image of DSSCs with Nb2O5 layer (a) with EDX mapping(이미지참조) 74
Figure 33. J-V curve of DSSC with blocking layer on TiO₂. 75
Figure 34. SEM images of blocking layer inside of TiO₂. he added amount of Nb2O5 solution is (a) 5 wt%, (b) 10 wt%, and (c) 20 wt%.(이미지참조) 77
Figure 35. TEM and EDX images of Nb2O5 mixed TiO₂ powder. The added amount of Nb2O5 solution is (a) 10 wt%, and (b) 20 wt%.(이미지참조) 79
Figure 36. FIB/SEM images of working electrode. The electron blocking layer was placed inside of TiO₂. 80
Figure 37. The cross-sectional FIB/SEM image of DSSCs with Nb2O5 layer (a) with EDX mapping: (b) Si atom (c) Sn atom (d) Nb atom (e) Ti atom.(이미지참조) 81
Figure 38. J-V curve of DSSC with blocking layer inside of TiO₂. 82
Figure 39. FIB/SEM images of working electrode. electron blocking layer was placed on FTO and inside of TiO₂. 84
Figure 40. The cross-sectional FIB/SEM image of DSSCs with Nb2O5 layer (a) with EDX mapping: (b) Si atom (c) Sn atom (d) Nb atom (e) Ti atom.(이미지참조) 85
Figure 41. J-V curve of DSSC with blocking layer on FTO and inside of TiO₂. 86
Figure 42. Scheme of immobilization of QDs on the surface of TiO₂ layer. 89
Figure 43. The PL spectra of QDs on TiO₂ layer as a function of times for dipping in cysteine solution. 90
Figure 44. The PL spectra of QDs on TiO₂ layer as a function of times for dipping in QDs solution. 91
Figure 45. UV/Vis. absorption and PL spectra of QDs 92
Figure 46. The fluorescence microscopy image of TiO₂ film with(right) and without (left) immobilization of QDs. 93
Figure 47. The normalized PL spectra of QDs immobilized on TiO₂. 94
Figure 48. Photograph images of QDs immobilized on TiO₂. under (a) white light and (b) UV light 95
Figure 49. SEM images of the surface of TiO₂ layer with immobilization of (a) no QDs, (b) 490 QDs, (c) 555 QDs, and (d) 620 QDs. 96
Figure 50. The FIB/SEM images of working electrode with immobilization of (a) 490 QDs, (b) 555 QDs, and (c) 620 QDs. 97
Figure 51. The cross-sectional FIB/SEM image of QDSSCs with Nb2O5 layer (a) with EDX mapping: (b) Si atom (c) Sn atom (d) Nb atom (e) Ti atom. (f) S atom.(이미지참조) 98
Figure 52. The cross-sectional FIB/SEM image of QDSSCs with Nb2O5 layer (a) with EDX mapping: (b) Si atom (c) Sn atom (d) Nb atom (e) Ti atom. (f) S atom.(이미지참조) 99
Figure 53. The cross-sectional FIB/SEM image of QDSSCs with Nb2O5 layer (a) with EDX mapping: (b) Si atom (c) Sn atom (d) Nb atom (e) Ti atom. (f) S atom.(이미지참조) 100
Figure 54. J-V curve of QDSSCs with different linker molecule between TiO₂ and QDs. 103
Figure 55. J-V curve of QDSSCs with different electrolyte. 104
Figure 56. J-V curve of QDSSCs with electron blocking layer. 105