Investigation of Deep-Level Defects Lateral Distribution in Active Layers of Multicrystalline Silicon Solar Cells

MRS Advances ◽  
2017 ◽  
Vol 2 (53) ◽  
pp. 3141-3146 ◽  
Author(s):  
Vladimir G. Litvinov ◽  
Alexander V. Ermachikhin ◽  
Dmitry S. Kusakin ◽  
Nikolay V. Vishnyakov ◽  
Valery V. Gudzev ◽  
...  

ABSTRACTThe influence of deep level defects lateral distribution in active layers of multicrystalline Si-based standard solar cells is investigated. Multicrystalline p-type Si wafers with 156×156 mm dimensions and 200 μm thickness were used for SCs preparation. One type of solar cells with conversion efficiency 20.4% was studied using capacitance voltage characteristics method (C-V) and by current deep level transient spectroscopy (I-DLTS). From various places along the diagonal of solar cell’s substrate with 20.4% efficiency nine pieces with an area ∼20 mm2 were extracted and studied. I-DLTS spectra of the five pieces from solar cell were measured. The features of deep levels defects concentration lateral distribution along the SC’s surface were studied.

MRS Advances ◽  
2016 ◽  
Vol 1 (14) ◽  
pp. 911-916 ◽  
Author(s):  
Vladimir G. Litvinov ◽  
Nikolay V. Vishnyakov ◽  
Valery V. Gudzev ◽  
Nikolay B. Rybin ◽  
Dmitry S. Kusakin ◽  
...  

ABSTRACTThe influence of deep level defects (DLs) on the conversion efficiency of multicrystalline Si-based standard solar cells (SCs) is investigated. Multicrystalline p-type Si wafers with 156×156 mm dimensions and 200 μm thickness were used for SCs preparation. Three types of SCs with conversion efficiency 10%, 16.8% and 20.4% were studied using capacitance voltage characteristics method (C-V) and by current deep level transient spectroscopy (I-DLTS). The correlation between the total concentration of DLs and the values of the SCs conversion efficiency is found.


1995 ◽  
Vol 378 ◽  
Author(s):  
R.R. Bilyalov ◽  
B.M. Abdurakhmanov

AbstractThe effect of hydrogen passivation on photovoltaic performance of 1 MeV electron irradiated polycrystalline cast silicon solar cells is described. These cells were processed on cast p-type boron doped polycrystalline silicon substrates using standard technology. Passivation was made by low-energy hydrogen ion implantation on the front side. Cells performance was measured as a function of fluence, and it was found that the hydrogenated cell had the higher radiation resistance.Defect behavior were studied using deep level transient spectroscopy and infra-red spectroscopy. It was shown that the concentration of vacancies (Ec −0,09 eV), divacancies (Ec −0,23 eV) and A-centers (Ec −0,18 eV) is significantly lower in hydrogenated samples. This consistency strengthens the belief that hydrogen interacts with vacancy-type defects to prevent formation of the secondary radiation defects. It is confirmed by IR-measurements.


1987 ◽  
Vol 65 (8) ◽  
pp. 966-971 ◽  
Author(s):  
N. Christoforou ◽  
J. D. Leslie ◽  
S. Damaskinos

CdS–CuInSe2 solar cells, which have an efficiency of 9%, have been studied by current–voltage, capacitance–voltage, and capacitance-transient measurements over the temperature range 90–380 K. Deep-level transient spectroscopy analysis of the capacitance transient measurements reveals one majority carrier trap with an activation energy of 0.70 ± 0.02 eV. Although the present experiment cannot establish definitely if the trap is in the CdS or CuInSe2 layer, arguments are presented that it is a hole trap in the p-type CuInSe2 layer. Current–voltage measurements indicate a reversible increase in the reverse-bias leakage current with increasing temperature above 300 K. Evidence is presented that suggests that the rectifying barrier height in the CdS–CuInSe2 solar cell decreases rapidly with temperature above 300 K. Capacitance versus voltage measurements suggest that the depiction layer being studied is primarily in the CuInSe2, but the temperature dependence of the ionized charge concentration N(x) cannot be totally explained although one possible cause is suggested.


1996 ◽  
Vol 423 ◽  
Author(s):  
D. Haase ◽  
M. Schmid ◽  
A. Dörnen ◽  
V. Härle ◽  
H. Bolay ◽  
...  

AbstractWe studied by deep level transient spectroscopy (DLTS) and capacitance-voltage (CV) measurements the effects of doping (Zn, S), nitrogen implantation and annealing of n-type GaN grown on sapphire by MOVPE. The DLTS spectra of the as grown samples show two defect levels which are assumed to be identical with recently reported levels [10, 11]. In N-implanted GaN a third level is introduced which is not detectable in our as grown samples. This levels concentration follows the increasing N-implantation density. The depth profiles of its concentration correlate with the distribution of implantation defects expected from Monte-Carlo simulation. After annealing at 900°C for 60s the additional defect level vanishes. The DLTS spectrum then resembles those of annealed as grown samples. The n-type carrier concentration (CV measurements) increases in samples with low N-implantation dose. This implantation effect can be removed also with the RTA step. The increasing carrier concentration provides evidence that the N vacancy is a donor in GaN. For Zn and S doped GaN deep defect levels has been found, which are reported here.


2011 ◽  
Vol 178-179 ◽  
pp. 183-187
Author(s):  
Chi Kwong Tang ◽  
Lasse Vines ◽  
Bengt Gunnar Svensson ◽  
Eduard Monakhov

The interaction between hydrogen and the iron-boron pair (Fe-B) has been investigated in iron-contaminated boron-doped Cz-Si using capacitance-voltage measurements (CV) and deep level transient spectroscopy (DLTS). Introduction of hydrogen was performed by wet chemical etching and subsequent reverve bias annealing of Al Schottky diodes. The treatment led to the appearance of the defect level characteristic to interstitial iron (Fei) with a corresponding decrease in the concentration of the Fe-B pair. Concentration versus depth profiles of the defects show that dissociation of Fe-B occurs in the depletion region and capacitance-voltage measurements unveil a decrease in the charge carrier concentration due to passivation of B. These quantitative observations imply strongly that H promotes dissociation of Fe-B releasing Fei whereas no detectable passivation of Fe-B or Fei by H occurs.


1998 ◽  
Vol 510 ◽  
Author(s):  
Shabih Fatima ◽  
Jennifer Wong-Leung ◽  
John Fitz Gerald ◽  
C. Jagadish

AbstractSubthreshold damage in p-type Si implanted and annealed at elevated temperature is characterized using deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). P-type Si is implanted with Si, Ge and Sn with energies in the range of 4 to 8.5 MeV, doses from 7 × 1012to 1×1014cm−2and all annealed at 800°C for 15 min. For each implanted specie, DLTS spectra show a transition dose called threshold dose above which point defects transform in to extended defects. DLTS measurements have shown for the doses below threshold, a sharp peak, corresponding to the signature of point defects and for doses above threshold a broad peak indicating the presence of extended defects. This is found to be consistent with TEM analyses where no defects are seen for the doses below threshold and the presence of extended defects for the doses above threshold. This suggests a defect transformation regime where point defects present below threshold are acting like nucleating sites for the extended defects. Also the mass dependence on the damage evolution has been observed, where rod-like defects are observed in the case of Si and (rod-like defects and loops) for Ge and Sn despite the fact that peak concentration of vacancies for Ge and Sn are normalized to the peak number of vacancies for Si.


2003 ◽  
Vol 784 ◽  
Author(s):  
P. Victor ◽  
S. Saha ◽  
S. B. Krupanidhi

ABSTRACTBaTiO3 and Ba0.9Ca0.1TiO3 thin films were deposited on the p – type Si substrate by pulsed excimer laser ablation technique. The Capacitance – Voltage (C-V) measurement measured at 1 MHz exhibited a clockwise rotating hysteresis loop with a wide memory window for the Metal – Ferroelectric – Semiconductor (MFS) capacitor confirming the ferroelectric nature. The low frequency C – V measurements exhibited the response of the minority carriers in the inversion region while at 1 MHz the C – V is of a high frequency type with minimum capacitance in the inversion region. The interface states of both the MFS structures were calculated from the Castagne – Vaipaille method (High – low frequency C – V curve). Deep Level Transient Spectroscopy (DLTS) was used to analyze the interface traps and capture cross section present in the MFS capacitor. There were distinct peaks present in the DLTS spectrum and these peaks were attributed to the presence of the discrete interface states present at the semiconductor – ferroelectric interface. The distribution of calculated interface states were mapped with the silicon energy band gap for both the undoped and Ca doped BaTiO3 thin films using both the C – V and DLTS method. The interface states of the Ca doped BaTiO3 thin films were found to be higher than the pure BaTiO3 thin films.


1998 ◽  
Vol 555 ◽  
Author(s):  
V. I. Polyakov ◽  
A. I. Rukovishnikov ◽  
A. V. Khomich ◽  
B. L. Druz ◽  
D. Kania ◽  
...  

AbstractDiamond-like carbon films (DLC) 10–40 nm thick were deposited on quartz substrates on an interdigitated planar array of 20 μm Ni electrodes already prepared by lithographic techniques. The influence of the adsorbed molecules onte electrical properties of the thin DLC films was investigated. Current and capacitance-voltage characteristics were examined. Charge-based deep level transient spectroscopy (Q-DLTS) was used for study of adsorption and desorption processes. The strong sensitivity of Q-DLTS spectra to the presence of the vapor water and isopropyl alcohol was found. For example, the Q-DLTS signal for some deposited DLC film was changed more then in order in presence of the water vapor. Such strong surface phenomena of the thin DLC films may be exploited in novel gas sensor devices.


2003 ◽  
Vol 763 ◽  
Author(s):  
Jehad A. AbuShama ◽  
S. Johnston ◽  
R. Ahrenkiel ◽  
R. Crandall ◽  
D. Young ◽  
...  

AbstractWe investigated the electronic properties of ZnO/CdS/CIGS/Mo/SLG polycrystalline thin-film solar cells with compositions ranging from Cu-rich to In(Ga)-rich by deep-level transient spectroscopy (DLTS) and capacitance-voltage (C-V) measurements. This compositional change represents the evolution of the film during growth by the 3-stage process. Two sets (four samples each) of CIGS thin films were prepared with Ga/(In+Ga) ratios of ∼0.3 (low Ga) and ∼0.6 (high Ga). The Cu/(In+Ga) ratio ranges from 1.24 (Cu-rich) to 0.88 (In(Ga)-rich). The films were treated with NaCN to remove the Cu2-xSe phase where needed. Key results include: (1) For lowGa devices, DLTS data show that acceptor-like traps dominate in samples where CIGS grains do not go through the Cu-rich to In(Ga)-rich transition, whereas donor-like traps dominate in In(Ga)-rich samples. Therefore, we see a clear transformation of defects from acceptor-like to donor-like traps. The activation energies of these traps range from 0.12 to 0.63 eV. We also observed that NaCN treatment eliminates a deep minority trap in the In(Ga)-rich devices, (2) For high-Ga devices, only majority-carrier traps were detected. These traps again range from shallow to deep, (3) The carrier concentration around the junction and the density of traps decrease as the CIGS becomes more In(Ga)-rich.


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