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Arno Smets Solar Cell Operation Design Rules: utilization of band gap energy Week 3.4
Arno Smets
Solar Cell OperationDesign Rules: utilization of band gap energy
Week 3.4
2. Spectral Utilization
Design Rules Solar Cells
1. Band Gap Utilization
3. Light Trapping
Delicate Interplay
2. Spectral Utilization
Design Rules Solar Cells
1. Band Gap Utilization
3. Light Trapping
Delicate Interplay
2. Spectral Utilization
Design Rules Solar Cells
1. Band Gap Utilization
3. Light Trapping
Delicate Interplay
2. Spectral Utilization
Design Rules Solar Cells
1. Band Gap Utilization
3. Light Trapping
Delicate Interplay
p
n
EFn
EFp
qVoc
Band gap utilization
1ln
0JJ
qTkV PHB
OC
p
n
EFn
EFp
qVoc
Band gap utilization
1ln
0JJ
qTkV PHB
OC
Voc 2kT
qln
GL0
ni
Charge Carrier Recombination
Radiative Auger SRH
Charge Carrier Recombination
Shockley Read Hall1
0 tN
Voc 2kT
qln
GL0
ni
Charge Carrier Recombination
Radiative Auger SRH
Charge Carrier Recombination
Relectron
kn2p e ,Aug
pR 1kn2
Rhole
kp2n h,Aug
nR 1kp2
Charge Carrier Recombination
Relectron
kn2p e ,Aug
pR 1kn2
Rhole
kp2n h,Aug
nR 1kp2
Charge Carrier Recombination
Momentum
Energy
Indirect band gap
photonphonon
Momentum
Energy
Direct band gap
photon
Momentum
Energy
Indirect band gap: c‐Si
photonphonon
Momentum
Energy
Direct band gap: GaAs
photon
Band gap utilization: .....the Voc is limited by
Radiative Auger SRH
Defect‐rich absorber layer
Band gap utilization: .....the Voc is limited by
Radiative Auger SRH
Defect‐free indirect band gap
Band gap utilization: .....the Voc is limited by
Radiative Auger SRH
Defect‐free direct band gap
Diffusion Length
Diffusion length:
p‐doped
Le De e Lh ehhh LDL
n‐doped
---
- - -- - -- - -
+ + + +
+ + + +
+ + + +
Minority carrier diffusion length
Ld
Relation between diffusion length and typical thickness of solar cells
Ld
p
n
EFn
EFp
qVoc
