Application of Wide Band Gap Semiconductors to Increase Photocurrent in a Protein Based Photovoltaic Device

2012 ◽  
Vol 1414 ◽  
Author(s):  
Arash Takshi ◽  
Houman Yaghoubi ◽  
Daniel Jun ◽  
Rafael Saer ◽  
Ali Mahmoudzadeh ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Indium Tin Oxide ◽  
Wide Band ◽  
Photocurrent Density ◽  
Wide Bandgap ◽  
Semiconducting Materials ◽  
Wide Band Gap ◽  
Electron Hole ◽  
New Approach ◽  
Wide Band Gap Semiconductors

ABSTRACTReaction centers (RCs) from natural photosynthetic cells are photoactive proteins, which generate electron-hole pairs in presence of light. In a new approach presented in this work, a solution of suspended RCs with mediators has been applied as the electrolyte to build electrochemical based photovoltaic (PV) devices. In this approach, the mediators transfer charges from the RCs to the electrodes (indirect charge transfer). Various metallic and wide bandgap semiconducting materials, including Carbon, Au, Indium Tin Oxide (ITO), SnO2, WO3, have been tested as the electrodes. Among all WO3, which is a semiconductor, have shown the largest photocurrent density with an amount of ∼5.1 μA/cm2. The results show that the material of the electrode can affect the rates of the reactions in the cell. Choosing an appropriate material for the electrode, the charge transfer from the mediators to the electrode would be rectified to achieve a large photocurrent.

Characterization of defects and impurities in wide band gap semiconductors by cathodoluminescence in TEM

1991 ◽  
Vol 49 ◽  
pp. 836-837
Author(s):  
R.J. Graham
Keyword(s):  
Band Gap ◽  
Wide Band ◽  
Optically Active ◽  
Semiconducting Materials ◽  
Electronic Information ◽  
Wide Band Gap ◽  
Low Concentrations ◽  
Wide Band Gap Semiconductors ◽  
Gan On Si

As a characterization technique for semiconductors, cathodoluminescence (CL) performed in TEM has several useful advantages over the more common SEM-based technique, the most important being that the acquisition of CL data from localized regions in an electron transparent specimen allows a correlation of microstructural and optical/electronic information. For example, it is possible to determine the distribution of low concentrations of optically active impurities and their possible association with defects, often at submicron resolution. Examples of TEM CL as a method of characterizing defects in semiconducting materials presented here are taken from wide band gap materials which are of current interest including CVD-grown diamond films and β-GaN on Si.

A New Approach to Growth of Bulk Zno Crystals for Wide Bandgap Applications

1998 ◽  
Vol 512 ◽  
Author(s):  
G. Agarwal ◽  
J. E. Nause ◽  
D. N. Hill
Keyword(s):  
Zinc Oxide ◽  
Single Crystal ◽  
Low Cost ◽  
Large Diameter ◽  
Wide Band ◽  
Wide Bandgap ◽  
Wide Band Gap ◽  
New Approach ◽  
Zinc Oxide Powder ◽  
Zno Single Crystal

ABSTRACTA novel technique was used to melt zinc oxide powder. This techniques involves the pressurized RF induction heating of ZnO, contained in a water-cooled crucible. The ability to obtain a pool of molten ZnO enables the pulling of large diameter ZnO crystals using conventional melt growth processes. Centimeter-sized crystals were obtained in the preliminary experiments by cooling the ZnO melt. These crystals were analyzed for crystalline perfection and stoichiometry using x-ray diffiraction and photoluminescence. The semiconductor properties of these crystals were also measured. This technology can potentially provide large, low cost ZnO single crystal wafers for use in the fabrication of GaN blue diodes and blue lasers, high temperature / high power FETs, as well as homoepitaxy of ZnO wide band-gap devices. Single crystal zinc oxide also has potential application in the piezoelectric device market.

UV p-i-n PHOTODIODES MADE ON WIDE BANDGAP SEMICONDUCTORS

2008 ◽  
Vol 22 (05) ◽  
pp. 369-381
Author(s):  
FERDINAND V. GASPARYAN
Keyword(s):  
Room Temperature ◽  
Function Versus ◽  
Wide Band ◽  
Negative Resistance ◽  
Wide Bandgap ◽  
Current Voltage Characteristic ◽  
Wide Band Gap ◽  
Current Voltage ◽  
Wide Band Gap Semiconductors ◽  
Bandgap Semiconductors

In this paper, results of investigations on the static and dynamic characteristics, responsivity, internal noises, detectivity and noise equivalent power of the forward biased p-i-n photodiode made on wide band gap semiconductors operating in double injection regime are presented. Numerical simulations were made for 4H-SiC and GaN . It is shown that forward biased p-i-n photodiodes have high values of responsivity (~ 0.03 A/W for 4H-SiC and ~ 0.15 A/W for GaN ), detectivity (~1011 cm Hz 1/2 W-1 for 4H-SiC and ~ 8×1013 cm Hz 1/2 W-1 for GaN ) and low level of internal noises at room temperature. It is shown also that dynamic negative resistance on the current–voltage characteristic can come into existence and that the reactive part of the impedance is the sign-changed function versus frequency.

scholarly journals Charge-Transfer Induced by the Oxygen Vacancy Defects in the Ag/MoO3 Composite System

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1292
Author(s):  
Qi Chu ◽  
Jingmeng Li ◽  
Sila Jin ◽  
Shuang Guo ◽  
Eungyeong Park ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Oxygen Vacancy ◽  
Composite System ◽  
Wide Band ◽  
Utilization Rate ◽  
Wide Band Gap ◽  
Interesting Phenomenon ◽  
Vacancy Defects ◽  
Characterization Methods ◽  
Surface Enhanced Raman

In this paper, an Ag/MoO3 composite system was cosputtered by Ar plasma bombardment on a polystyrene (PS) colloidal microsphere array. The MoO3 formed by this method contained abundant oxygen vacancy defects, which provided a channel for charge transfer in the system and compensated for the wide band gap of MoO3. Various characterization methods strongly demonstrated the existence of oxygen vacancy defects and detected the properties of oxygen vacancies. 4-Aminothiophenol (p-aminothiophenol, PATP) was used as a candidate surface-enhanced Raman scattering (SERS) probe molecule to evaluate the contribution of the oxygen vacancy defects in the Ag/MoO3 composite system. Interestingly, oxygen vacancy defects are a kind of charge channel, and their powerful effect is fully reflected in their SERS spectra. Increasing the number of charge channels and increasing the utilization rate of the channels caused the frequency of SERS characteristic peaks to shift. This interesting phenomenon opens up a new horizon for the study of SERS in oxygen-containing semiconductors and provides a powerful reference for the study of PATP.

A pathway to p-type wide-band-gap semiconductors

2009 ◽  
Vol 95 (17) ◽  
pp. 172109 ◽  
Author(s):  
Anderson Janotti ◽  
Eric Snow ◽  
Chris G. Van de Walle
Keyword(s):  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Wide Band Gap Semiconductors ◽  
P Type

scholarly journals Solid solubility of rare earth elements (Nd, Eu, Tb) in In2−xSnxO3 – effect on electrical conductivity and optical properties

2014 ◽  
Vol 43 (25) ◽  
pp. 9620-9632 ◽  
Author(s):  
T. O. L. Sunde ◽  
M. Lindgren ◽  
T. O. Mason ◽  
M.-A. Einarsrud ◽  
T. Grande
Keyword(s):  
Electrical Conductivity ◽  
Optical Properties ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Band Gap ◽  
Solid Solubility ◽  
Wide Band ◽  
Wide Band Gap ◽  
Recent Interest ◽  
Wide Band Gap Semiconductors

Wide band-gap semiconductors doped with luminescent rare earth elements (REEs) have attracted recent interest due to their unique optical properties.

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