Bandgap engineered high mobility indium oxide thin films for photovoltaic applications

2011 ◽  
Vol 1315 ◽  
Author(s):  
R.K. Gupta ◽  
K. Ghosh ◽  
P.K. Kahol

ABSTRACTMagnesium and titanium doped indium oxide (IMTO) thin films were grown using pulsed laser deposition technique. Magnesium was added to enhance the bandgap, whereas titanium was added to improve carrier concentrations and mobility of indium oxide films. The effect of growth temperature on structural, optical, and electrical properties were studied. It was observed that the optical transparency of the films strongly depends on growth temperature and increases with increase in growth temperature. The films grown at 600 °C showed optical transparency > 85%. We observed widening in bandgap of indium oxide by doping with magnesium and titanium. The bandgap of IMTO films increases with increase in growth temperature. The maximum bandgap of 3.9 eV was observed for film grown at 600 °C. It was observed that growth temperature strongly affects the electrical properties such as resistivity, carrier concentration, and mobility. The electrical resistivity and mobility of the films increases with increase in growth temperature. On the other hand, carrier concentration decreases with increase in growth temperature. Temperature dependence electrical resistivity measurements showed that films grown at low temperatures are semiconducting in nature, while films grown at high temperature showed transition from semiconducting to metallic behavior. These wide bandgap, highly transparent, and high mobility films could be used for photovoltaic applications.

2007 ◽  
Vol 1030 ◽  
Author(s):  
Ram Gupta ◽  
K. Ghosh ◽  
S. R. Mishra ◽  
P. K. Kahol

AbstractTransparent conducting oxides (TCO) have been widely used for opto-electronic devices such as light emitting diodes, photo-detectors, touch panels, flat panel displays, and solar cells. Low resistivity, high mobility, and good transparency are the prime requirements for these devices. There is an increasing interest in TCO with high mobility to decrease their electrical resistivity without a significant decrease in the optical transparency. Highly conducting and transparent tungsten doped indium oxide thin films were deposited on quartz substrate by ablating the sintered In2O3 target containing WO3 with a KrF excimer laser (λ = 248 nm and pulsed duration of 20 ns). The effect of growth temperature and oxygen pressure on structural, optical, and electrical properties has been studied. The transparency of the films largely depends on the growth temperature. The electrical properties are found to depend strongly on the growth temperature as well as on oxygen pressure. The temperature dependence resistivity measurement shows the transition from semiconductor to metallic behavior as the growth temperature increases from room temperature to 500 °C. The high mobility (up to 358 cm2V−1s−1), low resistivity (1.1 × 10−4 Ω.cm), and relatively high transmittance of ∼90 % have been observed on the optimized film grown at 500 °C and under oxygen pressure at 1 × 10−6 bar.


Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 715 ◽  
Author(s):  
Zhi-Yue Li ◽  
Sheng-Chi Chen ◽  
Qiu-Hong Huo ◽  
Ming-Han Liao ◽  
Ming-Jiang Dai ◽  
...  

In-Sn-Zn oxide (ITZO) thin films have been studied as a potential material in flat panel displays due to their high carrier concentration and high mobility. In the current work, ITZO thin films were deposited on glass substrates by high-power impulse magnetron sputtering (HiPIMS) at room temperature. The influence of the sputtering power on the microstructures and electrical performance of ITZO thin films was investigated. The results show that ITZO thin films prepared by HiPIMS were dense and smooth. There were slight variations in the composition of ITZO thin films deposited at different sputtering powers. With the sputtering power increasing from 100 W to 400 W, the film’s crystallinity was enhanced. When the sputtering power was 400 W, an In2O3 (104) plane could be detected. Films with optimal electrical properties were produced at a sputtering power of 300 W, a carrier mobility of 31.25 cm2·V−1·s−1, a carrier concentration of 9.11 × 1018 cm−3, and a resistivity of 2.19 × 10−4 Ω·m.


Author(s):  
J.P.S. Hanjra

Tin mono selenide (SnSe) with an energy gap of about 1 eV is a potential material for photovoltaic applications. Various authors have studied the structure, electronic and photoelectronic properties of thin films of SnSe grown by various deposition techniques. However, for practical photovoltaic junctions the electrical properties of SnSe films need improvement. We have carried out investigations into the properties of flash evaporated SnSe films. In this paper we report our results on the structure, which plays a dominant role on the electrical properties of thin films by TEM, SEM, and electron diffraction (ED).Thin films of SnSe were deposited by flash evaporation of SnSe fine powder prepared from high purity Sn and Se, onto glass, mica and KCl substrates in a vacuum of 2Ø micro Torr. A 15% HF + 2Ø% HNO3 solution was used to detach SnSe film from the glass and mica substrates whereas the film deposited on KCl substrate was floated over an ethanol water mixture by dissolution of KCl. The floating films were picked up on the grids for their EM analysis.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 692
Author(s):  
Jong Hyeon Won ◽  
Seong Ho Han ◽  
Bo Keun Park ◽  
Taek-Mo Chung ◽  
Jeong Hwan Han

Herein, we performed a comparative study of plasma-enhanced atomic layer deposition (PEALD) of SnO2 films using Sn(dmamp)2 as the Sn source and either H2O plasma or O2 plasma as the oxygen source in a wide temperature range of 100–300 °C. Since the type of oxygen source employed in PEALD determines the growth behavior and resultant film properties, we investigated the growth feature of both SnO2 PEALD processes and the various chemical, structural, morphological, optical, and electrical properties of SnO2 films, depending on the oxygen source. SnO2 films from Sn(dmamp)2/H2O plasma (SH-SnO2) and Sn(dmamp)2/O2 plasma (SO-SnO2) showed self-limiting atomic layer deposition (ALD) growth behavior with growth rates of ~0.21 and 0.07–0.13 nm/cycle, respectively. SO-SnO2 films showed relatively larger grain structures than SH-SnO2 films at all temperatures. Interestingly, SH-SnO2 films grown at high temperatures of 250 and 300 °C presented porous rod-shaped surface morphology. SO-SnO2 films showed good electrical properties, such as high mobility up to 27 cm2 V−1·s−1 and high carrier concentration of ~1019 cm−3, whereas SH-SnO2 films exhibited poor Hall mobility of 0.3–1.4 cm2 V−1·s−1 and moderate carrier concentration of 1 × 1017–30 × 1017 cm−3. This may be attributed to the significant grain boundary and hydrogen impurity scattering.


2021 ◽  
Author(s):  
Chunhu Zhao ◽  
Junfeng Liu ◽  
Yixin Guo ◽  
Yanlin Pan ◽  
Xiaobo Hu ◽  
...  

Abstract Aluminum doped ZnO thin films (AZO), which simultaneously transmit light and conduct electrical current, are widely applied in photovoltaic devices. To achieve high performance AZO thin films, the effects of RF magnetron sputtering conditions on the optical and electrical properties of the films has been explored. The optimized AZO thin films exhibit strong (002) orientated growth with hexagonal wurtzite structure. The minimum resistivity of 0.9Í10-3 Ω·cm, the highest carrier concentration of 2.8Í1020 cm-3, the best Hall mobility of 22.8 cm2·(V·s)-1 and average transmittance above 85% can be achieved at the optimum deposition condition of 0.2 Pa, 120 W and 200 °C. Considering the single parabolic band model, the bandgap shift by carrier concentration of the films can be attributed to the Burstein-Moss effect. The results indicate that RF magnetron sputtered AZO thin films are promising for solar cell applications relying on front contact layers.


2013 ◽  
Vol 774-776 ◽  
pp. 954-959
Author(s):  
Xiao Jing Wang

The electrical properties need to be improved, although Aluminum doped ZnO thin films (ZnO: Al) have been successfully deposited on transparent TPT substrates by our group. In this paper, ZnO: Al film was deposited on TPT substrate with SiO2 buffer layer by RF magnetron sputtering. The obtained film had a hexagonal structure and highly (002) preferred orientation. Compared with ZAO film without buffer layer, the lattice constant distortion of the film with buffer layer was decreased and the compressive stress was decreased by 9.2%, reaching to 0.779GPa. The carrier concentration and hall mobility of the film with buffer layer were both increased; especially the carrier concentration was enhanced by two orders of magnitude, reaching to 2.65×10+20/cm3. The resistivity of ZAO film with SiO2 buffer layer was about 7.6×10-3 Ω·cm and the average transmittance was over 70% in the range of 450~900nm.


2012 ◽  
Vol 38 ◽  
pp. S613-S616 ◽  
Author(s):  
Y. Seki ◽  
Y. Sawada ◽  
M.H. Wang ◽  
H. Lei ◽  
Y. Hoshi ◽  
...  

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