scholarly journals Decoupling bulk and surface recombination properties in silicon by depth-dependent carrier lifetime measurements

2021 ◽  
Vol 118 (25) ◽  
pp. 252105
Author(s):  
K. Yokoyama ◽  
J. S. Lord ◽  
J. Miao ◽  
P. Murahari ◽  
A. J. Drew
Keyword(s):  
Carrier Lifetime ◽  
Surface Recombination ◽  
Lifetime Measurements

Temperature Dependence of the Carrier Lifetime in 4H-SiC Epilayers

2010 ◽  
Vol 645-648 ◽  
pp. 203-206 ◽  
Author(s):  
Paul B. Klein ◽  
Rachael L. Myers-Ward ◽  
Kok Keong Lew ◽  
Brenda L. VanMil ◽  
Charles R. Eddy ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Carrier Lifetime ◽  
Surface Recombination ◽  
Surface Trap ◽  
Surface Band ◽  
Lifetime Measurements ◽  
Band Bending ◽  
Deep Defect ◽  
Surface Recombination Rate ◽  
Recombination Processes

The temperature dependence of the carrier lifetime was measured in n-type 4H-SiC epilayers of varying Z1/2 deep defect concentrations and layer thicknesses in order to investigate the recombination processes controlling the carrier lifetime in low- Z1/2 material. The results indicate that in more recently grown layers with lower deep defect concentrations, surface recombination tends to dominate over carrier capture by other bulk defects. Low-injection lifetime measurements were also found to provide a convenient method to assess the surface band bending and surface trap density in samples with a significant surface recombination rate.

Microscopic FCA System for Depth-Resolved Carrier Lifetime Measurement in SiC

2018 ◽  
Vol 924 ◽  
pp. 269-272 ◽  
Author(s):  
Shinichi Mae ◽  
Takeshi Tawara ◽  
Hidekazu Tsuchida ◽  
Masashi Kato
Keyword(s):  
Carrier Lifetime ◽  
Laser Light ◽  
Probe Laser ◽  
Free Carrier Absorption ◽  
Cross Sectional ◽  
Lifetime Measurements ◽  
Control Distribution ◽  
System A ◽  
Excitation Laser ◽  
Carrier Absorption

For high voltage SiC bipolar devices, carrier lifetime is an important parameter, and for optimization of device performance, we need to control distribution of the carrier lifetime in a wafer. So far, there have been limited systems for depth-resolved carrier lifetime measurements without cross sectional cut. In this study, we adopted a free carrier absorption technique and made local overlapping of the probe laser light with excitation laser light to develop depth-resolved carrier lifetime measurements. We named the developed system a microscopic FCA system and demonstrated measurement results for samples with and without intentional carrier lifetime distribution.

Carrier Lifetime Measurements by Photoconductance at Low Temperature on Passivated Crystalline Silicon Wafers

2013 ◽  
Vol 1536 ◽  
pp. 119-125 ◽  
Author(s):  
Guillaume Courtois ◽  
Bastien Bruneau ◽  
Igor P. Sobkowicz ◽  
Antoine Salomon ◽  
Pere Roca i Cabarrocas
Keyword(s):  
Low Temperature ◽  
Electron Mobility ◽  
Carrier Density ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
Crystalline Silicon ◽  
Silicon Wafers ◽  
Doping Density ◽  
Lifetime Measurements ◽  
Effective Lifetime

ABSTRACTWe propose an implementation of the PCD technique to minority carrier effective lifetime assessment in crystalline silicon at 77K. We focus here on (n)-type, FZ, polished wafers passivated by a-Si:H deposited by PECVD at 200°C. The samples were immersed into liquid N2 contained in a beaker placed on a Sinton lifetime tester. Prior to be converted into lifetimes, data were corrected for the height shift induced by the beaker. One issue lied in obtaining the sum of carrier mobilities at 77K. From dark conductance measurements performed on the lifetime tester, we extracted an electron mobility of 1.1x104 cm².V-1.s-1 at 77K, the doping density being independently calculated in order to account for the freezing effect of dopants. This way, we could obtain lifetime curves with respect to the carrier density. Effective lifetimes obtained at 77K proved to be significantly lower than at RT and not to depend upon the doping of the a-Si:H layers. We were also able to experimentally verify the expected rise in the implied Voc, which, on symmetrically passivated wafers, went up from 0.72V at RT to 1.04V at 77K under 1 sun equivalent illumination.

scholarly journals Study on Annealing Process of Aluminum Oxide Passivation Layer for PERC Solar Cells

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1052
Author(s):  
Yu-Chun Huang ◽  
Ricky Wenkuei Chuang
Keyword(s):  
Carrier Lifetime ◽  
Defect Density ◽  
Surface Recombination ◽  
Chemical Vapor ◽  
Minority Carrier Lifetime ◽  
Atomic Layer ◽  
Film Structure ◽  
Open Circuit ◽  
Annealing Process ◽  
Surface Recombination Velocity

In this study, Atomic Layer Deposition (ALD) equipment was used to deposit Al2O3 film on a p-type silicon wafer, trimethylaluminum (TMA) and H2O were used as precursor materials, and then the post-annealing process was conducted under atmospheric pressure. The Al2O3 films annealed at different temperatures between 200–500 °C were compared to ascertain the effect of passivation films and to confirm the changes in film structure and thickness before and after annealing through TEM images. Furthermore, the negative fixed charge and interface defect density were analyzed using the C-V measurement method. Photo-induced carrier generation was used to measure the effective minority carrier lifetime, the implied open-circuit voltage, and the effective surface recombination velocity of the film. The carrier lifetime was found to be the longest (2181.7 μs) for Al2O3/Si post-annealed at 400 °C. Finally, with the use of VHF (40.68 MHz) plasma-enhanced chemical vapor deposition (PECVD) equipment, a silicon nitride (SiNx) film was plated as an anti-reflection layer over the front side of the wafer and as a capping layer on the back to realize a passivated emitter and rear contact (PERC) solar cell with optimal efficiency up to 21.54%.

Carrier Lifetime Measurements for a Solar Cell

2013 ◽  
pp. 112-122
Author(s):  
Chetan S. Solanki ◽  
Brij M. Arora ◽  
Juzer Vasi ◽  
Mahesh B. Patil
Keyword(s):  
Solar Cell ◽  
Carrier Lifetime ◽  
Lifetime Measurements
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