Collection of Excel Formulas SB                        
 
etch thickness by weight   density of silicon is 2.328 g/cm3  
  100 cm² square 100mm round   for a 1 inch sample  
weight (g) t (µm) t(µm) Start Weight (g) End Weight (g) weight diff (g) t (cm) t (µm)  
 
 
Resistivity Measurements  
Thickness (cm) Current (mA) Voltage- (mV) Voltage+ (mV) Resistivity Thickness (um)  
 
   
Average change in thickness for lots of wafers  
Start Weight End Weight Wafers weight (g) t (µm)      
 
 
S from W, teff, tb  
W (um) D (cm2/s) teff (µsec) tb (µsec) ts (µsec) S (cm/s)  
 
     
tb from teff, S, W      
W (um) D (cm2/s) teff (µsec) S ts (µsec) tb (µsec)  
 
 
teff from tb, S, W      
W (um) D (cm2/s) tb (µsec) S ts (µsec) teff (µsec)  
 
 
Lifetime at limit  
D (cm2/s) W (cm) taus (s)  
 
 
Seff from J0 and minority carrier density (unverified)  
J0 (A/cm²) delta n Seff (cm/s)  
 
   
   
   
   
Seff from J0 and base doping at 25C (PC1D uses 300K)  
J0 (A/cm²) N (cm-3) S (cm/s)
300K
S (cm/s)
25 K
 
1.00e-013 1.00e+015  
 
Calculation of n and Jo from two light intensities        
Sample id Isc (A) Area (cm²) Jsc (A/cm²) Voc (mV) n from shaded J0 (A/cm²) Shading Fraction      
shaded        
unshaded        
       
Calculation of Optimum Shading Level      
Isc (Shaded) Isc (Full) Optimum shading      
92.993 102.24      
 
Diffusivity from Mobilty  
Mobility (Vcm2/s) D (cm2/s)  
20.0    
 
Diffusion Length from Lifetime   For 1 ohm cm material  
D (cm2/s) tb (µsec) L (um)   tb (µsec) L (um)  
11 1000   30  
 
Lifetime From Diffusion Length  
D (cm2/s) L (um) tb (µsec)  
26.88 400  
 
Leff from S and L  
W (um) D (cm2/s) L (um) S (cm/s) S.L/D tanh(W/L) Leff (um)  
200 26.9 1400  
 
Calculation of n and Jo from two light intensities in PC1D. Rshunt can ruin the measurements so turn it off!  
Batch run from:two light levels.txt  
PriInsySS PriInsyTR1 PriInsyTR2 BaseIsc BasePmax BaseVoc   Area (cm²) Jsc (mA/cm²) Voc (mV) n from shaded J0 (A/cm²)  
0.1 0.1 0.1 -3.1474 1.61321 0.617331   1  
0.01 0.01 0.01 -3.15e-001 0.14469 0.557211    
 
Using PC1D to calculate n and J0 in the dark. Make sure all light, Rs, Rshunt are off  
Batch run from:two light levels.txt          
PriInsySS PriInsyTR1 PriInsyTR2 BaseIsc BasePmax BaseVoc   Area (cm²) Jsc (mA/cm²) Voc (mV) n J0 (A/cm²)  
0.1 0.1 1.00e-001 -3.1474 1.61 6.17e-001   100  
0.01 0.01 1.00e-002 -3.15e-001 0.14469 0.557211    
     
Calculation of mobility etc. Use solve to find at a particular resistivity  
Doping (cm-3)  
7.00e+014 resistivity for p-type      
max min Nref a Mobility Diff   Resistivty   target diff  
1417 60 9.64e+016 0.664 Electron Majority n-type 1  
1417 160 5.60e+016 0.647 Electron Minority  
470 37.4 2.82e+017 0.642 Hole Majority   p-type 0.78  
470 155 1.00e+017 0.9 Hole Minority  
             
Polynomial fits to find doping from resistivity boron doped Si      
res (ohm cm) doping (cm-3)        
7 fit for 0.2 to 200 ohm cm        
1.47 fit for 0.2 to 200 ohm cm using simpler cubic    
1.47 fit for doping 1e12 1e21        
 
Determination of bulk lifetime from emitter sat. current plus LLI lifetime  
NA
(cm-3)
J0
(A/cm²)
W
(cm)
J0term
(s-1)
1/J0term (s) tau eff (µs) tau bulk (µs)  
1.50e+016  
 
Find Voc from the excess carrier (Implied Voc)  
NA
(cm-3)
delta n
(cm-3)
Implied Voc  
1.40e+016 1.79e+016  
   
Calculation of Voc from Effective Lifetime  
Suns Optical Coeff Jph tau eff (s) W (cm) delta n Doping
(cm-3)
Implied Voc  
1.00e+000 1    
   
Calculation of Optical Correction Factor for QSS-PC      
Jsc (mA/cm²) Optical Generation (/s) Generation (/s) Jsc (mA/cm²) Optical Constant  
40  
 
Reflactivity Optical Trans  
0.22  
 
Effect of Rsh on Voc  
Jsc (A/cm²) Rsh (Ocm²) delta Voc (mV)  
0.034 100  
 
Effect of J02 and J01 on Voc  
Jsc (A/cm²) Vt (V) 25°C J01 (A/cm²) J02 (A/cm²) Voc J01 only (V) Voc J01 & J02 (V) delta Voc (V)  
0.033 0.02568 1.52e-012 2.80e-008  
 
Using Leff to get Voc  
Diffusivity Base Doping ni Jsc Leff Constant Job Joe max Voc  
cm²/s /cm³ /cm³ A/cm² µm for J0b A/cm² A/cm² volts  
3.00e-013  
 
Voc from J0 and Jsc      
Jsc J0 max Voc      
A/cm² A/cm² volts            
     
 
Auger Lifetime  
n p n0 p0 delta_n  
  1.00e+017 5.00e+013 2.00e+006 1.00e+017  
 
Calculation of Job  
Jb V  
4.20e-009 0.2237  
  ni   Base Doping  
Jb /cm³ n /cm³  
2.89e+007  
   
 
Simple Auger lifetime  
n C tb (µsec)  
1.00e+015 1.66e-030  
 
Surface Recombination velocity at HLI  
S from W, teff, tb    
W (um) D (cm2/s) teff (µsec) tb (µsec) ts (µsec) S (cm/s)  
1.00e+004  
     
Conductivity in LLI  
un + up deltaN deltaS   Rons  
1514 1.00e+015 0.251  
 
Termperature Sesitivity  
Vgo gamma Voc  
1.2 3 0.7   popular probes 0.635 and 1.588
 
Four Point Probe (simple sheet resistivity)  
Voltage (V) Current (Amps) Rsheet (ohm/sqr) Wafer Thickness (cm) Wafer Resistivity (ohm cm) Probe Spacing (cm) Corrected Resistivity  
       
   
 
Anti-Reflection Coatings  
Wavelength
(nm)
ARC thickness (nm) Substrate Refractive Index surrounding refractive index ARC Refractive Index Theta R2 R1 Reflection  
 
 
Absorption from the Extinction Coefficinet  
k Wavelength (nm) absorption coefficient (/m) absorption coefficient (/cm)  
0.43331 300  
 
Ideality Factor from Light and Shaded Curves  
Jsc (mA/cm²) Voc (mV) n from shaded J0 (A/cm²) Shading          
0.72 552          
10.50 562.5          
 
Series Resistance from Light and Shaded Curve  
Current Vshaded Vcurve  
22.4 512 485  
 
Series Resistance Losses in a Finger  
Length (cm) Current Density (A/cm2) Finger Spacing (cm) Metal Resistivity (ohm cm) Radius of Wire (cm) Wire Resistivity (ohm/cm) Resistive Loss in Wire(W) Ideal Power Output Fraction of Power Lost (%)  
1.7 0.02 0.1 5.00e-006 0.0723197373901
 
       
Series Resistance Losses in a Finger    
Length (cm) Current Density (A/cm2) Finger Spacing (cm) Metal Resistivity (ohm cm) Width of Wire (cm) Thickness (cm) Wire Resistivity (ohm/cm) Resistive Loss in Wire(W) Ideal Power Output Fraction of Power Lost (%)    
0.8 0.03 0.2 4.00e-006 0.1 2.00e-005  
     
 
Intrinsic Carrier Concentration  
Nc (cm-3) Nv (cm-3) Eg (eV) ni(300K)  
2.86e+019 3.10e+019 1.12  
 
Density of States in the Conduction Band  
Temperature (K) Nc (cm-3)  
300  
 
Density of States in the Valence Band  
Temperature (K) Nv (cm-3)  
300  
 
Area of a Quadralateral  
x1 y1 x2 y2 x3 y3 x4 y4 Area  
226 181 192 705 1058 755 1096 235  
 
 
n p n0 p0 Dn R Auger  
           
QSS Lifetime  
Thickness delta_n (cm-3) G (s-1)  
  3.93e+015  
Effect of amorphous layer conductivity on cell  
Thickness (cm) Conductivity (S/cm) current (A/cm2) Vdrop (V)  
3.00e-002 1.00e-006 0.05  
Effect of conductivity of base  
Thickness (cm) Resistivity (ohmcm) current (A/cm2) Vdrop (V)  
3.00e-002 2.00e+000 0.05  
 
Intrinsic Lifetime of Silicon  
Dn NA 1/t t (sec) t (µsec)  
1.00e+013 1.00e+016  
Dp ND 1/t t (sec) t (µsec)  
1.00e+015 3.50e+015  

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