Surface and bulk passivation of multicrystalline silicon solar cells by ...

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The Van Houten library has removed some of the personal information and all signatures from the approval page and biographical sketches of theses and dissertations in order to protect the identity of NJIT graduates and faculty.
ABSTRACT SURFACE AND BULK PASSIVATION OF MULTICRYSTALLINE SILICON SOLAR CELLS BY SILICON NITRIDE (H) LAYER: MODELING AND EXPERIMENTS by Chuan Li The objective of this dissertation is to study passivation effects and mechanisms in Si solar cells, specifically, the surface and bulk passivation by hydrogen-rich PECVD silicon nitride (SiΝ :Η) antireflection layer on multicrystalline silicon (me-Si) solar cells. The passivation of silicon surface can be achieved in two ways: by field-effect passivation and/or by neutralization of interface states. In other words, the deposition should result in a high value of fixed charge, Qf and /or a low value of interface state density, D1. The surface recombination velocity can be described by Shockley-Read-Hall (SRH) statistics. Current SRH formalisms have failed to explain the surface recombination mechanism in terms of injection level dependence as has been observed by lifetime measurements. Previous SRH modeling result shows that very high Qf (up to several 10 12/cm2) on the surface of Si wafer, induced by SiN X:H layer, leads to no injection level dependence of surface recombination velocity (SRV), which is in contradiction to experimental results. An alternative approach is needed to address this problem. A modified SRH formalism which includes the carrier recombination in the space-charge region was developed in this thesis to evaluate the recombination mechanism at SiΝ :Η-Si interface. Numerical modeling results indicate that, at low injection-levels, carrier recombination in the damaged layer is the dominant mechanism
Page 1: Copyright Warning & Restrictions Th
Page 5 and 6: SURFACE AND BULK PASSIVATION OF MUL
Page 7 and 8: APPROVAL PAGE SURFACE AND BULK PASS
Page 9 and 10: Chuan Li, B.L. Sopori, P. Rupnowski
Page 11 and 12: ACKNOWLEDGEMENT The work presented
Page 13 and 14: TABLE OF CONTENTS (Continued) Chapt
Page 15 and 16: LIST OF TABLES Table Page 2.1 Posit
Page 17 and 18: LIST OF FIGURES (Continued) Figure
Page 19 and 20: LIST OF FIGURES (Continued) Figure
Page 21 and 22: 2 percent; however, soon, more adva
Page 23 and 24: 4 Figure 1.1 World solar module pro
Page 25 and 26: 6 bond is called a hole. It too can
Page 27 and 28: 8 Figure 1.4 The I-V characteristic
Page 29 and 30: 10 First generation cells consist o
Page 31 and 32: 12 Basically, materials for manufac
Page 33 and 34: 14 Defects are generally categorize
Page 35 and 36: 16 copper, or nickel in concentrati
Page 37 and 38: 18 the SiNx:H layer during the ther
Page 39 and 40: CHAPTER 2 SILICON NITRIDE LAYER FOR
Page 41 and 42: 22 reflectance of polished Si can b
Page 43 and 44: 24 information is application-orien
Page 45 and 46: 26 film fed growth (EFG) ribbon sil
Page 47 and 48: 28 Figure 2.5 Deposition of SiΝ :
Page 49 and 50: 30 Figure 2.6 shows the dependence
Page 51 and 52: 32 atoms, the interface states are
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34 2.5 Bulk Passivation of Si by Si
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36 It was found that the bulk lifet
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CHAPTER 3 MODELING OF SURFACE RECOM
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40 Figure 3.2 Schematic diagram of
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42 σ and σp are the capture cross
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44 Qsi — charge density induced i
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47 Figure 3.5 The calculated depend
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49 * 10 Λ m; m is in a range from
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51 Na, sigma_n, sigma_p: enter x.xx
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53 Figure 3.7 Measured Seff(Δn) de
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55 curves converge to a single valu
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57 seen that, initially Ss decrease
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59 carrier recombination within the
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61 recombination in the SCR influen
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63 Figure 3.13 shows that: 1) after
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CHAPTER 4 MINORITY-CARRIER LIFETIME
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67 Figure 4.1 Α photograph of QSSP
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69 work. The most convenient is 1 m
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7Ι dependence of the minority carr
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73 It was tempting to assume that l
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75 resistivities and lifetime) do n
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77 5.2 Objective An electronic mode
Page 98 and 99:
79 Figure 5.2 is a photograph of a
Page 100 and 101:
81 impurity-gettering methods which
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83 distribution of local currents a
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85 modeling. Wafers were selected f
Page 106 and 107:
87 Figure 5.5 A comparison of (a) d
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89 alloying results in metallizatio
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91 (i) Defect clusters are the prim
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93 SiNX induced charge density on t
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APPENDIX I PROGRAMS TO CALCULATE SR
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97 phin = -ΕΙ - 1 / beta * log(nd
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99 ίter3 = 0 for xi=1 to nmax/2-1
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101 input "output file name {XXXXXX
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103 F (i) = (exp (beta * (phip - ph
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APPENDIX III COMPUTATIONAL METHOD F
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107 where, dscr is the width of the
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REFERENCES 1. E. Becquerel , C. R.
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44. L.L. Alt, S.W. Ing. Jr. and K.W
Page 132 and 133:
90. B.L. Sopori, Y. Zhang, and N.M.
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