Surface and bulk passivation of multicrystalline silicon solar cells by ...
Surface and bulk passivation of multicrystalline silicon solar cells by ... Surface and bulk passivation of multicrystalline silicon solar cells by ...
51 Na, sigma_n, sigma_p: enter x.xxxxeyy, x.xxxxeyy, x.xxxxeyy (with the commas) note the eyy is how the program understands scientific notation where eyy = 1 0^yy note! Na could be Nd if you 're using a different type, the Idea is the same step size, fine-tune: enter x.xxxx, x.xxxx (with the comas) a typical stepsize is 0.001, but it can be made smaller for more accuracy. a typcial fine tune is 1, .1, .2, .25, .5 etc. the program will calculate different delta n's by using the fine-tune example: if it's at 1x10^7 and the fine-tune is .1 then 1.00x10^7 1.10x10^7 1.20x10^7 etc 3.2.2 Modeling Results and Discussion As can be seen from the extended SRH surface recombination model, the effective SRV depends in a complex manner on the energy dependent interface state density Dit(Ε), the capture cross sections for electrons σn(Ε) and holes σp(Ε), the dielectric-induced charge density Qf, the substrate doping concentration Ndop, and the bulk injection level Δn.
52 3.2.2.1 Seff dependence on Dit. Low Seff of the PECVD SiΝ X :H-passiνated Si surface is attributed to the combining of moderately low density of interface states, and a high positive charge density. Both parameters are given in Table 2.1 for as-deposited and thermally treated silicon nitride films [68]. According to the SRH formalism, Seff will decrease by reducing the interface state density D1. In Figure 3.6, the dependence of Seff on Dit is shown for Ι Ω-cm p-Si wafer. Figure 3.6 Calculated effective surface recombination velocity Seff for p-Si surface as a function of the injection level Δn in the quasi-neutral bulk for different values of interface state density Dit. Input parameters: Doping concentration = 1 x 10 16 em-3 ; o;, = 1 x 10 -14cm2, σn =1 x 10 -16cm2; Qf= 1.3 x 10 11 cm -2 . Experimental results are consistent with this prediction. As can be seen from Figure 3.7, SiΝ :H films prepared by remote plasma or direct PECVD at high frequency (HF) provide much better surface passivation than nitride layers prepared at low frequency (LF). This is achieved by avoiding heavy ion bombardment during the deposition process, and consequently much lower Di t [56].
- 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
- Page 53 and 54: 34 2.5 Bulk Passivation of Si by Si
- Page 55 and 56: 36 It was found that the bulk lifet
- Page 57 and 58: CHAPTER 3 MODELING OF SURFACE RECOM
- Page 59 and 60: 40 Figure 3.2 Schematic diagram of
- Page 61 and 62: 42 σ and σp are the capture cross
- Page 63 and 64: 44 Qsi — charge density induced i
- Page 66 and 67: 47 Figure 3.5 The calculated depend
- Page 68 and 69: 49 * 10 Λ m; m is in a range from
- Page 72 and 73: 53 Figure 3.7 Measured Seff(Δn) de
- Page 74 and 75: 55 curves converge to a single valu
- Page 76 and 77: 57 seen that, initially Ss decrease
- Page 78 and 79: 59 carrier recombination within the
- Page 80 and 81: 61 recombination in the SCR influen
- Page 82 and 83: 63 Figure 3.13 shows that: 1) after
- Page 84 and 85: CHAPTER 4 MINORITY-CARRIER LIFETIME
- Page 86 and 87: 67 Figure 4.1 Α photograph of QSSP
- Page 88 and 89: 69 work. The most convenient is 1 m
- Page 90 and 91: 7Ι dependence of the minority carr
- Page 92 and 93: 73 It was tempting to assume that l
- Page 94 and 95: 75 resistivities and lifetime) do n
- Page 96 and 97: 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
- Page 102 and 103: 83 distribution of local currents a
- Page 104 and 105: 85 modeling. Wafers were selected f
- Page 106 and 107: 87 Figure 5.5 A comparison of (a) d
- Page 108 and 109: 89 alloying results in metallizatio
- Page 110 and 111: 91 (i) Defect clusters are the prim
- Page 112 and 113: 93 SiNX induced charge density on t
- Page 114 and 115: APPENDIX I PROGRAMS TO CALCULATE SR
- Page 116 and 117: 97 phin = -ΕΙ - 1 / beta * log(nd
- Page 118 and 119: 99 ίter3 = 0 for xi=1 to nmax/2-1
51<br />
Na, sigma_n, sigma_p: enter x.xxxxeyy, x.xxxxeyy, x.xxxxeyy (with the<br />
commas)<br />
note the eyy is how the program underst<strong>and</strong>s scientific<br />
notation<br />
where eyy = 1 0^yy<br />
note! Na could be Nd if you 're using a different type, the<br />
Idea is the same<br />
step size, fine-tune: enter x.xxxx, x.xxxx (with the comas)<br />
a typical stepsize is 0.001, but it can be made smaller for<br />
more<br />
accuracy.<br />
a typcial fine tune is 1, .1, .2, .25, .5 etc.<br />
the program will calculate different delta n's <strong>by</strong> using the<br />
fine-tune<br />
example: if it's at 1x10^7 <strong>and</strong> the fine-tune is .1 then<br />
1.00x10^7<br />
1.10x10^7<br />
1.20x10^7 etc<br />
3.2.2 Modeling Results <strong>and</strong> Discussion<br />
As can be seen from the extended SRH surface recombination model, the effective SRV<br />
depends in a complex manner on the energy dependent interface state density Dit(Ε), the<br />
capture cross sections for electrons σn(Ε) <strong>and</strong> holes σp(Ε), the dielectric-induced charge<br />
density Qf, the substrate doping concentration Ndop, <strong>and</strong> the <strong>bulk</strong> injection level Δn.
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