Theoretical design of SnS2-graphene heterojunction with vacancy and impurity defects for multi-purpose photoelectric devices

Author(s):  
Zhonghao Zhou ◽  
Jianjun Deng ◽  
Xingchen Zhang ◽  
Jinglong Chen ◽  
Jia Liu ◽  
...  

SnS2 with atomic thickness has attracted extensive attention in the field of photocatalysis due to its special physicochemical properties, suitable band gap, low cost and low environmental toxicity. However, the...

Author(s):  
Dinesh Pathak ◽  
Sanjay Kumar ◽  
Sonali Andotra ◽  
Jibin Thomas ◽  
Navneet Kaur ◽  
...  

In this study, we have investigated new tailored organic semiconductors materials for the optoelectronic application, such as organic solar cells. The carbon-based organic semiconductor material has promising advantages in organic thin-film form. Moreover, due to its low cost, organic thin-films are suitable and cheaper than inorganic thin-film. The band gap of organic semiconductors materials can be tuned and mostly lies between 2.0eV to 4eV and the optical absorption edge of organic semiconductors typically lies in between 1.7eV to 3eV. They can be easily tailored by modifying the carbon chain and legends and looks promising for engineering the band gap to harness solar spectrum. In this work, with new tailored organic semiconductors the solution route is explored which is low cost processing method. (Anthracen-9-yl) methylene naphthalene-1-amine, 4-(anthracen-9-ylmethyleneamino)-1,5dimethyl-2-phenyl-1H-pyrazol-3-one and N-(anthracen-9-ylmethyl)-3,4-dimethoxyaniline thin-films are processed by spin coating method with changing concentration such as 0.05 wt% and 0.08 wt%. Thin films of Organic semiconductors were prepared on glass substrate and annealed at 55°C. The structural and optical behaviour of (Anthracen-9-yl) methylene naphthalene-1-amine, 4-(anthracen-9-ylmethyleneamino)-1,5dimethyl-2-phenyl-1H-pyrazol-3-one and N-(anthracen-9-ylmethyl)-3,4-dimethoxyaniline organic semiconductors thin films is studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and UV-Visible Spectroscopy technique. The XRD data of synthesized sample suggests the Nano crystallinity of the Organic layers. The SEM micrographs shows the dense packing when we increase the wt% 0.05 to 0.08. Analysis of the optical absorption measurements found that the engineered band gap of synthesized thin films are 2.18eV, 2.35eV, 2.36eV, 2.52eV and 2.65eV which suggest suitability for applications of Optoelectronic devices such as solar cell. Such light weight, eco-friendly and disposable new carbon based materials seems to have potential to replace other traditional hazardous heavy materials for future eco-friendly flat fast electronics. Keywords: Thin-film, solar cell, tailored organic semiconductors, XRD, SEM, UV-Vis spectroscopy.


2014 ◽  
Vol 1670 ◽  
Author(s):  
Antony Jan ◽  
Yesheng Yee ◽  
Bruce M. Clemens

ABSTRACTThin-film absorber layers for photovoltaics have attracted much attention for their potential for low cost per unit power generation, due both to reduced material consumption and to higher tolerance for defects such as grain boundaries. Cu2ZnGeSe4 (CZGSe) comprises one such material system which has a near-optimal direct band gap of 1.6 eV for absorption of the solar spectrum, and is made primarily from earth-abundant elements.CZGSe metallic precursor films were sputtered from Cu, Zn, and Ge onto Mo-coated soda lime glass substrates. These were then selenized in a two-zone close-space sublimation furnace using elemental Se as the source, with temperatures in the range of 400 to 500 C, and at a variety of background pressures. Films approximately 1-1.5 µm thick were obtained with the expected stannite crystal structure.Next, Cu2ZnSnSe4 (CZTSe), which has a direct band gap of 1.0 eV, was prepared in a similar manner and combined with CZGSe as either compositionally homogeneous or layered absorbers. The compositional uniformity of selenide absorbers made by selenizing compositionally homogeneous Cu-Zn-Ge-Sn precursor layers was determined and the band gap as a function of composition was investigated in order to demonstrate that the band gap is tuneable for a range of compositions. For layered Cu-Zn-Ge/Cu-Zn-Sn precursor films, the composition profile was measured before and after selenization to assess the stability of the layered structure, and its applicability for forming a band-gap-graded device for improved current collection.


2020 ◽  
Vol 20 (6) ◽  
pp. 3622-3635 ◽  
Author(s):  
Kuldeep S. Gour ◽  
Rahul Parmar ◽  
Rahul Kumar ◽  
Vidya N. Singh

Cd is categorized as a toxic material with restricted use in electronics as there are inherent problems of treating waste and convincing consumers that it is properly sealed inside without any threat of precarious leaks. Apart from toxicity, band-gap of CdS is about 2.40–2.50 eV, which results significant photon loss in short-wavelength range which restricts the overall performance of solar cells. Thin film of Zn(O,S) is a favorable contender to substitute CdS thin film as buffer layer for CuInGaSe2 (CIGS), CuInGa(S,Se)2 (CIGSSe), Cu2ZnSn(S,Se)4 (CZTSSe) Cu2ZnSnSe4 (CZTSe), Cu2ZnSnS4 (CZTS) thin film absorber material based photovoltaic due to it made from earth abundant, low cost, non-toxic materials and its ability to improve the efficiency of chalcogenide and kesterite based photovoltaic due to wider band-gap which results in reduction of absorption loss compared to CdS. In this review, apart from mentioning various deposition technique for Zn(O,S) thin films, changes in various properties i.e., optical, morphological, and opto-electrical properties of Zn(O,S) thin film deposited using various methods utilized for fabricating solar cell based on CIGS, CIGSSe, CZTS, CZTSe and CZTSSe thin films, the material has been evaluated for all the properties of buffer layer (high transparency for incident light, good conduction band lineup with absorber material, low interface recombination, high resistivity and good device stability).


2019 ◽  
Vol 969 ◽  
pp. 439-443
Author(s):  
Ishwar Naik ◽  
Rajashekhar Bhajantri ◽  
B.S. Patil ◽  
Vinayak Bhat

Abstract.Plastic solar cells are promising devices in looking for low cost and flexible energy storing devices. Low efficiency is the main drawback of these cells in comparison with inorganic solar cells and hence the search for an efficient plastic solar cell has become a globally demanded research problem. In the present work we have used the modified fullerene [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) as N type modulating probe on P type semiconducting polymer Poly[2-methoxy-5-(2’-ethylhexyloxy)-phenylenevinylene] (MEH-PPV). The donor MEH-PPV polymer matrix is modulated by adding PCBM in the weight ratio 1:3, 1:1 and 3:1 in Chloro-Benzene(CB) as the common solvent and glass-coated samples are prepared by solution cast method. Samples are analyzed by UV-VISIBLE spectroscopy by JASCO UV Vis NIR V 670 spectrometer. The effect of PCBM content on MEH-PPV is to broaden the spectral response of MEH-PPV. In other words the acceptor PCBM has tuned the band gap (energy difference between HOMO & LUMO) of the donor MEH-PPV. Spectral analysis revealed that 1:3 blend of MEH-PPV with PCBM has a wide spectral sensitivity for absorption. The band gap for each blend is determined using Tauc’s plot. Increased Fullerene content has decreased the band gap of the host polymer. We conclude that modified fullerene can effectively modulate the donor polymer matrix and 1:3 MEH-PPV: PCBM can act as a good photoactive material for solar cells. Absorption can be further enhanced by either dye sensitization or by metal oxide nanoparticle doping without increasing the thickness of the film. We have doped the optimized 1:3 blend with 20%, 40% & 60% of TiO2 nanoparticles wherein the absorption is enhanced with doping level. The increased absorption is attributed to the photocatalytic activity of the nanaoparticles embedded in the polymer matrix


2019 ◽  
Vol 27 (01) ◽  
pp. 1950008 ◽  
Author(s):  
B. G. Prashantha ◽  
S. Seetharamu ◽  
G. S. V. L. Narasimham ◽  
M. R. Praveen Kumar

In this paper, the design of 50 W thermoacoustic refrigerators operating with air as working substance at 10 bar pressure and 3% drive ratio for a temperature difference of 28 K is described. The design strategies discussed in this paper help in design and development of low cost thermoacoustic coolers compared to helium as the working substance. The design and optimization of spiral stack and heat exchangers, and the promising 0.2[Formula: see text] and 0.15[Formula: see text] resonator design with taper and divergent section with hemispherical end are discussed. The surface area, volume, length and power density of the hemispherical end design with air as working substance is found better compared to the published 10 and 50 W coolers using helium as the working substance. The theoretical design results are validated using DeltaEC software simulation results. The DeltaEC predicts 51.4% improvement in COP (1.273) at the cold heat exchanger temperature of [Formula: see text]C with air as working substance for the 50[Formula: see text]W 0.15[Formula: see text]TDH resonator design compared to the published 50[Formula: see text]W 0.25[Formula: see text]TDH resonator design with helium as working substance.


2015 ◽  
Vol 1107 ◽  
pp. 678-683 ◽  
Author(s):  
Lam Mui Li ◽  
Azmizam Manie Mani ◽  
Saafie Salleh ◽  
Afishah Alias

Zinc Oxide (ZnO) has attracted much attention because of its high optical transmittance approximately ~80 % with a wide band gap of (3.3 eV at 300 K) and a relatively low cost material. ZnO thin films were deposited on plastic substrate using RF powered magnetron sputtering method. The target used is ZnO disk with 99.99 % purity. The sputtering processes are carried out with argon gas that flow from 10-15 sccm. Argon is used to sputter the ZnO target because the ability of argon that can remove ZnO layer effectively by sputtering with argon plasma bombardment. The deposited ZnO thin films are characterized using X-Ray Diffraction (XRD) and UV-Vis Spectrometer. The analysis of X-ray diffraction show that good crystalline quality occurs at nominal thickness of 400 nm. The optical studies showed that all the thin films have high average transmittance of approximately 80 % and the estimated value of optical band gap is within 3.1 eV-3.3 eV range.


2010 ◽  
Vol 43 ◽  
pp. 361-365
Author(s):  
Qing Yuan Sheng ◽  
Ping Ping Li ◽  
Xi Liang Zhang ◽  
Zhi Gang Liu ◽  
Li Juan Zhao ◽  
...  

Considering the greater character differences between matrix and soil, and the great disparity in physicochemical properties of various substrate, now there is no special equipment to test matrix moisture, electrical conductivity (EC) and salinity of medium .On the basis of analyzing physicochemical properties of various substrate, the relationship between output voltage and water content is studied through piezoelectric type soil moisture probe trial. With "voltage-current" four-terminal method, multi-parameter integrated sensor testing medium moisture and electrical conductivities developed, and through the solution calibration EC measuring model is established. Then relationships among matrix water content, electrical conductivity and salinity are analyzed, and salinity testing model is established. A portable low-cost in-situ multi-parameter detection apparatus, testing substrate humidity, EC and salinities, developed by adopting MCU SPCE06A. Experimental results indicate that detection accuracy of the equipment can meet the need of soilless culture production, and it has greater application and dissemination value.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jie Zhang ◽  
Bo Long ◽  
Shuying Cheng ◽  
Weibo Zhang

Copper zinc tin sulfur (CZTS) thin films have been extensively studied in recent years for their advantages of low cost, high absorption coefficient (≥104 cm−1), appropriate band gap (~1.5 eV), and nontoxicity. CZTS thin films are promising materials of solar cells like copper indium gallium selenide (CIGS). In this work, CZTS thin films were prepared on glass substrates by vacuum evaporation and sulfurization method. Sn/Cu/ZnS (CZT) precursors were deposited by thermal evaporation and then sulfurized in N2+ H2S atmosphere at temperatures of 360–560°C to produce polycrystalline CZTS thin films. It is found that there are some impurity phases in the thin films with the sulfurization temperature less than 500°C, and the crystallite size of CZTS is quite small. With the further increase of the sulfurization temperature, the obtained thin films exhibit preferred (112) orientation with larger crystallite size and higher density. When the sulfurization temperature is 500°C, the band gap energy, resistivity, carrier concentration, and mobility of the CZTS thin films are 1.49 eV, 9.37 Ω · cm,1.714×1017 cm−3, and 3.89 cm2/(V · s), respectively. Therefore, the prepared CZTS thin films are suitable for absorbers of solar cells.


2010 ◽  
Vol 25 (12) ◽  
pp. 2426-2429 ◽  
Author(s):  
Guangjun Wang ◽  
Gang Cheng ◽  
Binbin Hu ◽  
Xiaoli Wang ◽  
Shaoming Wan ◽  
...  

In this paper, polycrystalline CuIn(SxSe1–x)2 thin films with tunable x and Eg (band gap) values were prepared by controlling the sulfurization temperature (T) of CuInSe2 thin films. X-ray diffraction indicated the CuIn(SxSe1–x)2 films exhibited a homogeneous chalcopyrite structure. When T increases from 150 to 500 °C, x increases from 0 to 1, and Eg increases from 0.96 to 1.43 eV. The relations between x and Eg and the sulfurization process of CuIn(SxSe1–x)2 thin films have been discussed. This work provides an easy and low-cost technique for preparing large area absorber layers of solar cell with tunable Eg.


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