Separation of local bulk and surface recombination in crystalline silicon from luminescence reabsorption

2009 ◽  
Vol 18 (1) ◽  
pp. 10-19 ◽  
Author(s):  
J. A. Giesecke ◽  
M. Kasemann ◽  
M. C. Schubert ◽  
P. Würfel ◽  
W. Warta

2007 ◽  
Vol 46 (No. 47) ◽  
pp. L1149-L1151 ◽  
Author(s):  
Yu Takahashi ◽  
Hayato Kondo ◽  
Tsutomu Yamazaki ◽  
Yukiharu Uraoka ◽  
Takashi Fuyuki


2013 ◽  
Vol 4 ◽  
pp. 726-731 ◽  
Author(s):  
Gema López ◽  
Pablo R Ortega ◽  
Cristóbal Voz ◽  
Isidro Martín ◽  
Mónica Colina ◽  
...  

The aim of this work is to study the surface passivation of aluminum oxide/amorphous silicon carbide (Al2O3/a-SiCx) stacks on both p-type and n-type crystalline silicon (c-Si) substrates as well as the optical characterization of these stacks. Al2O3 films of different thicknesses were deposited by thermal atomic layer deposition (ALD) at 200 °C and were complemented with a layer of a-SiCx deposited by plasma-enhanced chemical vapor deposition (PECVD) to form anti-reflection coating (ARC) stacks with a total thickness of 75 nm. A comparative study has been carried out on polished and randomly textured wafers. We have experimentally determined the optimum thickness of the stack for photovoltaic applications by minimizing the reflection losses over a wide wavelength range (300–1200 nm) without compromising the outstanding passivation properties of the Al2O3 films. The upper limit of the surface recombination velocity (S eff,max) was evaluated at a carrier injection level corresponding to 1-sun illumination, which led to values below 10 cm/s. Reflectance values below 2% were measured on textured samples over the wavelength range of 450–1000 nm.





2006 ◽  
Vol 910 ◽  
Author(s):  
Mahdi Farrokh Baroughi ◽  
Siva Sivoththaman

AbstractThis paper presents a measurement technique for studying of the interface between a nanocrystalline silicon (nc-Si) film and a crystalline silicon (c-Si) substrate using microwave photoconductivity decay (MWPCD). The nc-Si films were deposited using plasma enhanced chemical vapor deposition of highly hydrogen-diluted silane. The films were deposited on both sides of the high purity float-zone (FZ) Si wafers. The high resolution transmission electron microscope (HRTEM) analysis of the interface and the characterization of the effective excess carrier lifetime of the samples using MWPCD revealed the following results: (i) The crystallinity of the deposited nc-Si films is very high. The nc-Si film follows the crystal orientation of the substrate such that not a well-defined boundary between nc-Si film and the c-Si substrate is observed. (ii) A surface recombination velocity of less than 10 cm/s was measured for the interface region of the nc-Si/c-Si junctions. (iii) A small discontinuity in the band-energy diagram of the interface region was observed.



1994 ◽  
Vol 65 (10) ◽  
pp. 1260-1262 ◽  
Author(s):  
H. C. Neitzert ◽  
N. Layadi ◽  
P. Roca i Cabarrocas ◽  
R. Vanderhaghen


2014 ◽  
Vol 1666 ◽  
Author(s):  
Jun Furukawa ◽  
Satoshi Shigeno ◽  
Shinya Yoshidomi ◽  
Tomohito Node ◽  
Masahiko Hasumi ◽  
...  

ABSTRACTWe report photo induced minority carrier annihilation at the silicon surface in a metal–oxide–semiconductor (MOS) structure using 9.35 GHz microwave transmittance measurement. 7 Ωcm n-type 500-μm-thick crystalline silicon substrate coated with 100-nm-thick thermally grown SiO2 layers was used. 0.2-cm-long Al electrode bars were formed at the top and rear surfaces. 635 nm light illumination onto the top surface caused photo induced carriers to be in one side of the silicon region of the Al electrode. Microwave transmittance system detected photo induced carriers diffused from the light illuminated region via the MOS structured region. When the bias voltage was applied at +2.0 and -2.2 V to the electrode at the top surface, the surface recombination velocity increased from 44 (initial) to 83 and 86 cm/s, respectively because of depletion region formation at rear and top surface respectively. Those voltage applications caused change in the distribution of photo induced carriers in a 0.6-cm-wide region including light illuminated, MOS structured, microwave irradiated regions.



2004 ◽  
Vol 808 ◽  
Author(s):  
D.H. Levi ◽  
C.W. Teplin ◽  
E. Iwaniczko ◽  
R.K. Ahrenkiel ◽  
H.M. Branz ◽  
...  

ABSTRACTWe have applied real-time spectroscopic ellipsometry (RTSE) as both an in-situ diagnostic and post-growth analysis tool for hydrogenated amorphous silicon (a-Si:H)/crystalline silicon (c-Si) heterojunction with intrinsic thin-layer (HIT) solar cells grown by hot-wire chemical vapor deposition. RTSE enables precise thickness control of the 5 to 25 nm layers used in these devices, as well as monitoring crystallinity and surface roughness in real time. Utilizing RTSE feedback, but without extensive optimization, we have achieved a photovoltaic energy conversion efficiency of 14.1% on an Al-backed p-type Czochralski c-Si wafer coated with thin i and n layers on the front. Open-circuit voltages above 620 mV indicate effective passivation of the c-Si surface by the a-Si:H intrinsic layer. Lifetime measurements using resonant coupled photoconductive decay indicate that surface recombination velocities can approach 1 cm/s. RTSE and transmission electron microscopy show that the intrinsic a-Si:H i-layers grow as a mixture of amorphous and nano-crystalline silicon.



2012 ◽  
Vol 51 (4S) ◽  
pp. 04DP06 ◽  
Author(s):  
Koji Arafune ◽  
Shohei Miki ◽  
Ryosuke Matsutani ◽  
Junpei Hamano ◽  
Haruhiko Yoshida ◽  
...  


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