The open circuit voltage in amorphous silicon p-i-n solar cells and its relationship to material, device and dark diode parameters

2004 ◽  
Vol 96 (4) ◽  
pp. 2261-2271 ◽  
Author(s):  
U. Dutta ◽  
P. Chatterjee
2011 ◽  
Vol 181-182 ◽  
pp. 328-331
Author(s):  
Ming Ji Shi ◽  
Lei Xiong ◽  
Lan Li Chen

It is necessary to improve the open circuit voltage of amorphous silicon solar cells for its applications. In this paper, we discuss the effects of hydrogen plasma treatment on the P layer and the performance of the amorphous silicon solar cells. The result shows that the open circuit voltage increased by 0.0257V, the fill factor increased by 0.039 and the energy conversion efficiency increased by 9%. The highest VOCwe got was 0.99V. Treating P layer with hydrogen plasma has been demonstrated to result in materials with improved crystalline volume fraction which was very effective to increase the light absorption of the intrinsic layer. What is more, it could be easily integrated into the amorphous silicon solar cell mass production process.


2003 ◽  
Vol 762 ◽  
Author(s):  
K. Zhu ◽  
J. Yang ◽  
W. Wang ◽  
E. A. Schiff ◽  
J. Liang ◽  
...  

AbstractWe describe a model for a-Si:H based pin solar cells derived primarily from valence bandtail properties. We show how hole drift-mobility measurements and measurements of the temperature-dependence of the open-circuit voltage VOC can be used to estimate the parameters, and we present VOC(T) measurements. We compared the power density under solar illumination calculated with this model with published results for as-deposited a-Si:H solar cells. The agreement is within 4% for a range of thicknesses, suggesting that the power from as-deposited cells is close to the bandtail limit.


2005 ◽  
Vol 862 ◽  
Author(s):  
Jianjun Liang ◽  
E. A. Schiff ◽  
S. Guha ◽  
B. Yan ◽  
J. Yang

AbstractWe present temperature-dependent measurements of the open-circuit voltage VOC(T) in hydrogenated amorphous silicon nip solar cells prepared at United Solar. At room-temperature and above, VOC measured using near-solar illumination intensity differs by as much as 0.04 V for the as-deposited and light-soaked states; the values of VOC for the two states converge below 250 K. Models for VOC based entirely on recombination through deep levels (dangling bonds) do not account for the convergence effect. The convergence is present in a model that assumes the recombination traffic in the as-deposited state involves only bandtails, but which splits the recombination traffic fairly evenly between bandtails and defects for the light-soaked state at room-temperature. Recombination mechanisms are important in understanding light-soaking, and the present results are inconsistent with at least one well-known model for defect generation.


1987 ◽  
Vol 95 ◽  
Author(s):  
N. T. Tran ◽  
F. R. Jeffrey ◽  
D. J. Olsen

AbstractCarbon grading in the buffer layer at the p/i interface increases the open circuit voltage of both p-i-n and n-i-p amorphous silicon solar cells. We propose that carbon grading enlarges the electric field and reduces the electron tunneling at the p/i interface.


2000 ◽  
Vol 609 ◽  
Author(s):  
Jeffrey Yang ◽  
Kenneth Lord ◽  
Subhendu Guha ◽  
S.R. Ovshinsky

ABSTRACTA systematic study has been made of amorphous silicon (a-Si) alloy solar cells using various hydrogen dilutions during the growth of the intrinsic (i) layer. We find that the open-circuit voltage (Voc) of the cells increases as the dilution increases; it then reaches a maximum before it decreases dramatically. This sudden drop in Voc is attributed to the transition from amorphous silicon to microcrystalline inclusions in the i layer. We study i-layer thicknesses ranging from 1000 Å to 5000 Å and find that the transition occurs in all thicknesses investigated. Based on this study, a-Si alloy p i n solar cells suitable for use in the top cell of a high efficiency triple-junction structure are made. By selecting an appropriate dilution, cells with Voc greater than 1 V can be achieved readily. Solar cells made near the threshold not only exhibit higher initial characteristics but also better stability against light soaking. We have compared top cells made near the threshold with our previous best data, and found that both the initial and stable efficiencies are superior for the near-threshold cells. For an a-Si/a-Si double-junction device, a Voc value exceeding 2 V has been obtained using thin component cells. Thicker component cells give rise to an initial active-area efficiency of 11.9% for this tandem structure.


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