Structural and Electrical Properties of ZnO Films Deposited with Low-Temperature Facing Targets Magnetron Sputtering (FTS) System with Changes in H2 and O2 Flow Rate

2013 ◽  
Vol 13 (11) ◽  
pp. 7745-7750
Author(s):  
Hye Ran Kim ◽  
Su Bong Jin ◽  
Long Wen ◽  
Yoon Seok Choi ◽  
In Sik Choi ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Low Temperature ◽  
Magnetron Sputtering ◽  
Flow Rate ◽  
Zno Films ◽  
Structural And Electrical Properties

Effects of fluorine incorporation on the structural and electrical properties of Diamond-like carbon

2015 ◽  
Vol 1734 ◽  
Author(s):  
Kento Nakanishi ◽  
Jun Otsuka ◽  
Masanori Hiratsuka ◽  
Chen Chung Du ◽  
Akira Shirakura ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Electrical Properties ◽  
Flow Rate ◽  
Gas Flow ◽  
Diamond Like Carbon ◽  
Gas Flow Rate ◽  
Sheet Resistivity ◽  
Nitrogen Doped ◽  
Structural And Electrical Properties

ABSTRACTDiamond-like carbon (DLC) has widespread attention as a new material for its application to thin film solar cells and other semiconducting devices. DLC can be produced at a lower cost than amorphous silicon, which is utilized for solar cells today. However, the electrical properties of DLC are insufficient for this purpose because of many dangling bonds in DLC. To solve this problem, we investigated the effects of the fluorine incorporation on the structural and electrical properties of DLC.We prepared five kinds of fluorinated DLC (F-DLC) thin film with different amounts of fluorine. Films were deposited by the radio-frequency plasma enhanced chemical vapor deposition (RF-PECVD) method. C6H6 and C6HF5 were used as source gases. The total gas flow rate was constant and the gas flow rate ratio R (=C6H6 / (C6H6 + C6HF5)) was changed from 0 to 1 in 0.25 ratio steps. We also prepared nitrogen doped DLC (F-DLC) on p-Si using N2 gas as a doping gas to form nitrogen doped DLC (F-DLC) / p-Si heterojunction diodes.X-ray photoelectron spectroscopy (XPS) showed that fluorine concentration in the DLC films was controlled. Moreover, the XPS analysis of the C1s spectrum at R=2/4 showed the presence of CF bonding. At R=1, CF2 bonding was observed in addition to CF bonding. The sheet resistivity of the films changed from 3.07×1012 to 4.86×109 Ω. The minimum value was obtained at R=2/4. The current-voltage characteristics indicated that nitrogen doped F-DLC of 2/4 and p-Si heterojunction diode exhibited the best rectification characteristics and its energy conversion efficiency had been maximized. This is because of a decrease of dangling bonds density by ESR analysis and an increase of sp2 structures by Raman analysis. When the fluorine is over certain content, the sheet resistivity increases because chain structures become larger, which is due to the CF2 bonding in F-DLC prevents ring structures. Many C2F4 species were observed and it may become precursors of the chain structure domains, such as (CF2)n.In this study, we revealed effects of fluorine incorporation on DLC and succeeded in increasing its conductivity and improving rectification characteristics of DLC/ p-Si hetero-junction diodes. Our results indicate that DLC fluorination is effective for the semiconducting material, such as solar cell applications.

Processing and Characterization of Amorphous Copper Oxide Thin Films Prepared by Reactive Magnetron Sputtering

2018 ◽  
Vol 775 ◽  
pp. 238-245 ◽  
Author(s):  
Thitinai Gaewdang ◽  
Ngamnit Wongcharoen
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Magnetron Sputtering ◽  
Copper Oxide ◽  
Flow Rate ◽  
Localized States ◽  
Positive Sign ◽  
Variable Range Hopping ◽  
Variable Range ◽  
Deposited Films

In this paper, copper oxide (CuOx) thin films with amorphous phase were prepared on glass substrates by reactive dc magnetron sputtering. The influence of the flow rate of O2 on the structural, optical and electrical properties of the as-deposited films was systematically studied. XRD revealed that the as-deposited films remained amorphous in the whole range of adjusted oxygen flow rate. Surface morphology and nanoparticle size of the films were observed by AFM. Electrical resistivity and Hall effect measurements were performed on the films with van der Pauw configuration. The positive sign of the Hall coefficient confirmed the p-type conductivity in all studied films. From temperature-dependent electrical conductivity of the films prepared at R(O2) of 1.5 sccm, it was show that three types of behavior can be expected, nearest-neighbor hopping at high temperature range (200-300 K), the Mott variable range hopping at low temperature (110-190 K) and Efros-Shklovskii variable range hopping at very low temperature (65-100 K). Some important parameters corresponding to Mott-VRH and ES-VRH like density of localized states near the Fermi level, localization length, degree of disorder, hopping distance and hopping energy were determined. These parameters would be helpful for optimizing the performance of photovoltaic applications.

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