scholarly journals Superstrate Structured FTO/TiO2/In2S3/Cu2ZnSnS4 Solar Cells Fabricated by a Spray Method with Aqueous Solutions

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 548 ◽  
Author(s):  
Dongho Lee ◽  
JungYup Yang

Copper Zinc Tin Sulfide (C2ZTS4) solar cells have become a fascinating research topic due to several advantages of the C2ZTS4 absorber layer, such as having non-toxic and abundantly available components. Superstrate structured C2ZTS4 solar cells were fabricated on the top of a fluorine-doped tin oxide (FTO) substrate with a spray pyrolysis method from the window layer to the absorber layer. Titanium dioxide (TiO2) and indium sulfide (In2S3) were used as the window and buffer layer, respectively. The source materials for the C2ZTS4 and buffer layers were all aqueous-based solutions. The metallic component ratio, Cu/(Zn + Sn), and the sulfur concentration in the solutions were systematically investigated. The optimum ratio of Cu/(Zn + Sn) in the film is about 0.785, while 0.18 M thiourea in the solution is the best condition for high performance. The C2ZTS4 layers deposited at lower temperatures (<360 °C) yielded a low quality resulting in low current density (JSC). On the other hand, the C2ZTS4 layers deposited at high temperature (~400 °C) showed a low fill factor (FF) without degradation of the open-circuit voltage (VOC) and JSC due to the junction degradation and high contact resistance between the absorber layer and metal contact. The best cell efficiency, VOC, JSC, and fill factor achieved were 3.34%, 383 mV, 24.6 mA/cm2, and 37.7%, respectively.

MRS Advances ◽  
2019 ◽  
Vol 4 (16) ◽  
pp. 913-919 ◽  
Author(s):  
Fadhil K. Alfadhili ◽  
Adam B. Phillips ◽  
Geethika K. Liyanage ◽  
Jacob M. Gibbs ◽  
Manoj K. Jamarkattel ◽  
...  

ABSTRACTFormation of a low barrier back contact plays a critical role in improving the photoconversion efficiency of the CdTe solar cells. Incorporating a buffer layer to minimize the band bending at the back of the CdTe device can significantly lower the barrier for the hole current, improving open circuit voltage (VOC) and the fill factor. Over the past years, researchers have incorporated the both ZnTe and Te as buffer layers to improve CdTe device performance. Here we compare device performance using these two materials as buffer layers at the back of CdTe devices. We show that using Te in contact to CdTe results in higher performance than using ZnTe in contact to the CdTe. Low temperature current density-voltage measurements show that Te results is a lower barrier with CdTe than ZnTe, indicating that Te has better band alignment, resulting in less downward bending in the CdTe at the back interface, than ZnTe does.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Pao-Hsun Huang ◽  
Chien-Jung Huang ◽  
Kan-Lin Chen ◽  
Jhong-Ciao Ke ◽  
Yeong-Her Wang ◽  
...  

An optimized hybrid planar heterojunction (PHJ) of small molecule organic solar cells (SM-OSCs) based on copper phthalocyanine (CuPc) as donor and fullerene (C60) as acceptor was fabricated, which obviously enhanced the performance of device by sequentially using both MoO3and pentacene as double anode buffer layers (ABL), also known as hole extraction layer (HEL). A series of the vacuum-deposited ABL, acting as an electron and exciton blocking layer, were examined for their characteristics in SM-OSCs. The performance and reliability were compared between conventional ITO/ABL/CuPc/C60/BCP/Ag cells and the new ITO/double ABL/CuPc/C60/BCP/Ag cells. The effect on the electrical properties of these materials was also investigated to obtain the optimal thickness of ABL. The comparison shows that the modified cell has an enhanced reliability compared to traditional cells. The improvement of lifetime was attributed to the idea of double layers to prevent humidity and oxygen from diffusing into the active layer. We demonstrated that the interfacial extraction layers are necessary to avoid degradation of device. That is to say, in normal temperature and pressure, a new avenue for the device within double buffer layers has exhibited the highest values of open circuit voltage (Voc), fill factor (FF), and lifetime in this work compared to monolayer of ABL.


Author(s):  
Omar Ghanim Ghazal ◽  
Ahmed Waleed Kasim ◽  
Nabeel Zuhair Tawfeeq

Cadmium telluride (CdTe)/cadmium sulfide (CdS) solar cell is a promising candidate for photovoltaic (PV) energy production, as fabrication costs are compared by silicon wafers. We include an analysis of CdTe/CdS solar cells while optimizing structural parameters. Solar cell capacitance simulator (SCAPS)-1D 3.3 software is used to analyze and develop energy-efficient. The impact of operating thermal efficiency on solar cells is highlighted in this article to explore the temperature dependence. PV parameters were calculated in the different absorber, buffer, and window layer thicknesses (CdTe, CdS, and SnO2). The effect of the thicknesses of the layers, and the fundamental characteristics of open-circuit voltage, fill factor, short circuit current, and solar energy conversion efficiency were studied. The results showed the thickness of the absorber and buffer layers could be optimized. The temperature had a major impact on the CdTe/CdS solar cells as well. The optimized solar cell has an efficiency performance of &gt;14% when exposed to the AM1.5 G spectrum. CdTe 3000 nm, CdS 50 nm, SnO2 500 nm, and (at) T 300k were the I-V characteristics gave the best conversion open circuit voltage (Voc)=0.8317 volts, short circuit current density (Jsc)=23.15 mA/cm2, fill factor (FF)%=77.48, and efficiency (η)%=14.73. The results can be used to provide important guidance for future work on multi-junction solar cell design.


2021 ◽  
Vol 13 (21) ◽  
pp. 12320
Author(s):  
Mamta ◽  
Kamlesh Kumar Maurya ◽  
Vidya Nand Singh

In an Sb2Se3-based solar cell, the buffer layer is sandwiched between the absorber and the window layer, playing an essential role in interfacial electricity. Generally, CdS is used as a buffer layer, but its toxic nature and low bandgap can cause current loss because of parasitic absorption. In this work, we optimized the buffer layer by using ZnS as an alternative to the CdS buffer layer in order to decrease the use of CdS. The effect of different buffer layers on the solar device was explored by numerical simulation with the help of SCAPS 1D software. The basic parameters, such as open-circuit voltage (Voc), current density (Jsc), fill factor (FF), and efficiency (η) were analyzed and compared for both the buffer layers (CdS/ZnS). The results demonstrate that changing buffer materials and thicknesses has a significant impact on cell performance. The efficiency for the ZnS buffer layer was lower compared to that of the CdS-based solar cells because of insufficient energy band alignment. In order to enhance the efficiency of Sb2Se3-based solar cells, we used CdS/ZnS dual buffer layers and studied the device performance. The work function of the back contact also affects the device performance, and for work functions below 4.8 eV, the device’s efficiency was very low. The effect of varying the thicknesses and temperatures of the buffer layers on the I-V/C-V characteristics, quantum efficiency, and energy band structure are also reported. This study shall guide the researcher in reducing CdS and improving the device’s performance.


2003 ◽  
Vol 762 ◽  
Author(s):  
Jianhua Zhu ◽  
Vikram L. Dalal

AbstractWe report on the growth and properties of microcrystalline Si:H and (Si,Ge):H solar cells on stainless steel substrates. The solar cells were grown using a remote, low pressure ECR plasma system. In order to crystallize (Si,Ge), much higher hydrogen dilution (∼40:1) had to be used compared to the case for mc-Si:H, where a dilution of 10:1 was adequate for crystallization. The solar cell structure was of the p+nn+ type, with light entering the p+ layer. It was found that it was advantageous to use a thin a-Si:H buffer layer at the back of the cells in order to reduce shunt density and improve the performance of the cells. A graded gap buffer layer was used at the p+n interface so as to improve the open-circuit voltage and fill factor. The open circuit voltage and fill factor decreased as the Ge content increased. Quantum efficiency measurements indicated that the device was indeed microcrystalline and followed the absorption characteristics of crystalline ( Si,Ge). As the Ge content increased, quantum efficiency in the infrared increased. X-ray measurements of films indicated grain sizes of ∼ 10nm. EDAX measurements were used to measure the Ge content in the films and devices. Capacitance measurements at low frequencies ( ~100 Hz and 1 kHz) indicated that the base layer was indeed behaving as a crystalline material, with classical C(V) curves. The defect density varied between 1x1016 to 2x1017/cm3, with higher defects indicated as the Ge concentration increased.


2003 ◽  
Vol 762 ◽  
Author(s):  
Guozhen Yuea ◽  
Baojie Yan ◽  
Jeffrey Yang ◽  
Kenneth Lord ◽  
Subhendu Guha

AbstractWe have observed a significant light-induced increase in the open-circuit voltage (Voc) of mixed-phase hydrogenated silicon solar cells. In this study, we investigate the kinetics of the light-induced effects. The results show that the cells with different initial Voc have different kinetic behavior. For the cells with a low initial Voc (less than 0.8 V), the increase in Voc is slow and does not saturate for light-soaking time of up to 16 hours. For the cells with medium initial Voc (0.8 ∼ 0.95 V), the Voc increases rapidly and then saturates. Cells with high initial Voc (0.95 ∼ 0.98 V) show an initial increase in Voc, followed bya Voc decrease. All light-soaked cells exhibit a degradation in fill factor. The temperature dependence of the kinetics shows that light soaking at high temperatures causes Voc increase to saturate faster than at low temperatures. The observed results can be explained by our recently proposed two-diode equivalent-circuit model for mixed-phase solar cells.


2013 ◽  
Vol 665 ◽  
pp. 330-335 ◽  
Author(s):  
Ripal Parmar ◽  
Dipak Sahay ◽  
R.J. Pathak ◽  
R.K. Shah

The solar cells have been used as most promising device to convert light energy into electrical energy. In this paper authors have attempted to fabricate Photoelectrochemical solar cell with semiconductor electrode using TMDCs. The Photoelectrochemical solar cells are the solar cells which convert the solar energy into electrical energy. The photoelectrochemical cells are clean and inexhaustible sources of energy. The photoelectrochemical solar cells are fabricated using WSe2crystal and electrolyte solution of 0.025M I2, 0.5M NaI, 0.5M Na2SO4. Here the WSe2crystals were grown by direct vapour transport technique. In our investigations the solar cell parameters like short circuit current (Isc) and Open circuit voltage (Voc) were measured and from that Fill factor (F.F.) and photoconversion efficiency (η) are investigated. The results obtained shows that the value of efficiency and fill factor of solar cell varies with the illumination intensities.


Author(s):  
Nur Shakina Mohd Shariff ◽  
Puteri Sarah Mohamad Saad ◽  
Mohamad Rusop Mahmood

There has been an increasing interest towards organic solar cells after the discovery of conjugated polymer and bulk-heterojunction concept. Eventhough organic solar cells are less expensive than inorganic solar cells but the power conversion energy is still considered low. The main objective of this research is to investigate the effect of the P3HT’s thickness and concentration towards the efficiency of the P3HT:Graphene solar cells. A simulation software that is specialize for photovoltaic called SCAPS is used in this research to simulate the effect on the solar cells. The solar cell’s structure will be drawn inside the simulation and the parameters for each layers is inserted. The result such as the open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), efficiency (η), capacitance-voltage (C-V) and capacitance-frequency (C-f) characteristic will be calculated by the software and all the results will be put into one graph.


2001 ◽  
Vol 665 ◽  
Author(s):  
V. Dyakonov ◽  
I. Riedel ◽  
C. Deibel ◽  
J. Parisi ◽  
C. J. Brabec ◽  
...  

ABSTRACTWe studied the electronic transport properties of conjugated polymer/fullerene based solar cells by means of temperature and illumination intensity dependent current-voltage characteristics, admittance spectroscopy and light-induced electron spin resonance. The short-circuit current density increases with temperature at all light illumination intensities applied, i.e., from 100 mW/cm2 to 0.1 mW/cm2 (white light), whereas a temperature independent behavior was expected. An increase of the open-circuit voltage from 850 mV to 940 mV was observed, when cooling down the device from room temperature to 100 K. The fill factor depends strongly on temperature with a positive temperature coefficient in the whole temperature range. In contrast, the light intensity dependence of the fill factor shows a maximum of 52% at intermediate illumination intensities (3 mW/cm2) and decreases subsequently, when increasing the intensity up to 100 mW/cm2. Further studies by admittance spectroscopy revealed two frequency dependent contributions to the device capacitance. One, as we believe, originates from trapping states located at the interface between composite and metal electrode with an activation energy of EA=180 meV, and the other one is from very shallow bulk states with EA=10 meV. The origin of the latter is possibly the thermally activated conductivity. The photo-generation of charge carriers and their fate in these blends have been studied by light-induced electron spin resonance. We can clearly distinguish between photo-generated electrons and holes in the composites due to different spectroscopic splitting factors (g-factors). Additional information on the environmental axial symmetry of the holes located on the polymer chains as well as on a lower, rhombic, symmetry of the electrons located on the methanofullerene molecules has been obtained. The origin of the signals and parameters of the g-tensor have been confirmed from studies on a hole doped polymer.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1123 ◽  
Author(s):  
Guanggen Zeng ◽  
Xia Hao ◽  
Shengqiang Ren ◽  
Lianghuan Feng ◽  
Qionghua Wang

The application of thinner cadmium sulfide (CdS) window layer is a feasible approach to improve the performance of cadmium telluride (CdTe) thin film solar cells. However, the reduction of compactness and continuity of thinner CdS always deteriorates the device performance. In this work, transparent Al2O3 films with different thicknesses, deposited by using atomic layer deposition (ALD), were utilized as buffer layers between the front electrode transparent conductive oxide (TCO) and CdS layers to solve this problem, and then, thin-film solar cells with a structure of TCO/Al2O3/CdS/CdTe/BC/Ni were fabricated. The characteristics of the ALD-Al2O3 films were studied by UV–visible transmittance spectrum, Raman spectroscopy, and atomic force microscopy (AFM). The light and dark J–V performances of solar cells were also measured by specific instrumentations. The transmittance measurement conducted on the TCO/Al2O3 films verified that the transmittance of TCO/Al2O3 were comparable to that of single TCO layer, meaning that no extra absorption loss occurred when Al2O3 buffer layers were introduced into cells. Furthermore, due to the advantages of the ALD method, the ALD-Al2O3 buffer layers formed an extremely continuous and uniform coverage on the substrates to effectively fill and block the tiny leakage channels in CdS/CdTe polycrystalline films and improve the characteristics of the interface between TCO and CdS. However, as the thickness of alumina increased, the negative effects of cells were gradually exposed, especially the increase of the series resistance (Rs) and the more serious “roll-over” phenomenon. Finally, the cell conversion efficiency (η) of more than 13.0% accompanied by optimized uniformity performances was successfully achieved corresponding to the 10 nm thick ALD-Al2O3 thin film.


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