Temperature Dependent Study of Carrier Diffusion in Photon Enhanced Thermionic Emission Solar Converters

2013 ◽  
Vol 772 ◽  
pp. 634-639
Author(s):  
Yang Yang ◽  
Wen Zheng Yang ◽  
Wei Dong Tang ◽  
Chuan Dong Sun
Keyword(s):  
Solar Energy ◽  
Temperature Dependence ◽  
Carrier Transport ◽  
Elevated Temperatures ◽  
Thermionic Emission ◽  
Back Surface ◽  
Optical Parameters ◽  
Material Parameters ◽  
Novel Concept ◽  
P Type

Photon Enhanced Thermionic Emission (PETE) is a novel concept in solar energy conversion, which can efficiently harvest solar energy at elevated temperatures. However, the temperature dependence of material parameters has not been clearly stated so far. In this study, a model for carrier transport is presented based on one dimension diffusion equation. Material data of GaAs are used to testify the temperature impact on material parameters. We find that for higher doped p-type GaAs which is suitable for PETE cathode material, its electron diffusion length shows weak temperature dependence. Carrier transport efficiency can be boosted by optimizing the geometry of the cathode and the optical parameters of the material. Finally, we propose a design of reflective mode cathode with reflective back surface and nanostructure emissive surface for PETE application.

Investigation of carrier transport mechanisms in the Cu–Zn–Se based hetero-structure grown by sputtering technique

2018 ◽  
Vol 96 (7) ◽  
pp. 816-825 ◽  
Author(s):  
H.H. Güllü ◽  
M. Terlemezoğlu ◽  
Ö. Bayraklı ◽  
D.E. Yıldız ◽  
M. Parlak
Keyword(s):  
Barrier Height ◽  
Carrier Transport ◽  
Thermionic Emission ◽  
Electrical Characterization ◽  
Band Gap Energy ◽  
Zero Bias ◽  
Hetero Structure ◽  
Current Voltage ◽  
P Type

In this paper, we present results of the electrical characterization of n-Si/p-Cu–Zn–Se hetero-structure. Sputtered film was found in Se-rich behavior with tetragonal polycrystalline nature along with (112) preferred orientation. The band gap energy for direct optical transitions was obtained as 2.65 eV. The results of the conductivity measurements indicated p-type behavior and carrier transport mechanism was modelled according to thermionic emission theory. Detailed electrical characterization of this structure was carried out with the help of temperature-dependent current–voltage measurements in the temperature range of 220–360 K, room temperature, and frequency-dependent capacitance–voltage and conductance-voltage measurements. The anomaly in current–voltage characteristics was related to barrier height inhomogeneity at the interface and modified by the assumption of Gaussian distribution of barrier height, in which mean barrier height and standard deviation at zero bias were found as 2.11 and 0.24 eV, respectively. Moreover, Richardson constant value was determined as 141.95 Acm−2K−2 by means of modified Richardson plot.

TEMPERATURE DEPENDENCE OF ELECTRICAL CHARACTERISTICS OF Cr/p–Si(100) SCHOTTKY BARRIER DIODES

2008 ◽  
Vol 22 (14) ◽  
pp. 2309-2319 ◽  
Author(s):  
K. ERTURK ◽  
M. C. HACIISMAILOGLU ◽  
Y. BEKTORE ◽  
M. AHMETOGLU
Keyword(s):  
Temperature Dependence ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Thermionic Emission ◽  
Electrical Characteristics ◽  
Schottky Barrier Diodes ◽  
Semiconductor Interface ◽  
Linear Portion ◽  
Barrier Heights ◽  
P Type

The electrical characteristics of Cr / p – Si (100) Schottky barrier diodes have been measured in the temperature range of 100–300 K. The I-V analysis based on thermionic emission (TE) theory has revealed an abnormal decrease of apparent barrier height and increase of ideality factor at low temperature. The conventional Richardson plot exhibits non-linearity below 200 K with the linear portion corresponding to activation energy 0.304 eV and Richardson constant (A*) value of 5.41×10-3 Acm-2 K -2 is determined from the intercept at the ordinate of this experimental plot, which is much lower than the known value of 32 Acm-2 K -2 for p-type Si . It is demonstrated that these anomalies result due to the barrier height inhomogeneities prevailing at the metal-semiconductor interface. Hence, it has been concluded that the temperature dependence of the I-V characteristics of the Cr/p – Si Schottky barrier diode can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the barrier heights. Furthermore, the value of the Richardson constant found is much closer than that obtained without considering the inhomogeneous barrier heights.

scholarly journals Temperature-Dependent Analysis of Solid-State Photon-Enhanced Thermionic Emission Solar Energy Converter

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1554
Author(s):  
Yang Yang ◽  
Wei Wei Cao ◽  
Peng Xu ◽  
Bing Li Zhu ◽  
Yong Lin Bai ◽  
...  
Keyword(s):  
Solid State ◽  
Solar Energy ◽  
High Temperatures ◽  
Open Circuit Voltage ◽  
Elevated Temperatures ◽  
Electrical Power ◽  
Thermionic Emission ◽  
Open Circuit ◽  
Temperature Dependent ◽  
Doping Density

Solid-state photon-enhanced thermionic emission (PETE) solar energy converters are newly proposed devices that can directly convert solar energy into electrical power at high temperatures. An analytical model based on a one-dimensional steady-state equation is developed to analyze the temperature-dependent performance of the solid-state PETE converter. The treatment used to derive the reverse saturation current density ( J 0 ) and open-circuit voltage ( V o c ) of the solid-state PETE converter is similar to that used in photovoltaic cells. Thus, their performances at elevated temperatures can be compared. Analysis results show that J 0 of the solid-state PETE converter with a GaAs absorption layer is approximately three orders of magnitude lower, and the decrease rate of open-circuit voltage ( − d V o c / d T ) is smaller than that of a practical GaAs photovoltaic cell. The improved performance of the solid-state PETE converter at high temperatures is attributed to the simultaneous use of diffusion and ballistic transport to harvest photo-generated electrons. The results presented in this paper demonstrate that, besides using wide bandgap materials and increasing doping density, harvesting solar energy via PETE effect can effectively improve the performance of solar cells at elevated temperatures.

Mechanism of Carrier Transport in n-Type β-FeSi2/Intrinsic Si/p-Type Si Heterojunctions

2015 ◽  
Vol 1119 ◽  
pp. 189-193
Author(s):  
Nathaporn Promros ◽  
Motoki Takahara ◽  
Ryuji Baba ◽  
Tarek M. Mostafa ◽  
Mahmoud Shaban ◽  
...  
Keyword(s):  
Ideality Factor ◽  
Carrier Transport ◽  
Linear Part ◽  
Forward Bias ◽  
Thermionic Emission ◽  
Forward Bias Voltage ◽  
Space Charge Limit ◽  
Current Voltage ◽  
P Type ◽  
Direct Current Sputtering

Preparation of n-type β-FeSi2/intrinsic Si/p-type Si heterojunctions was accomplished by facing-target direct-current sputtering (FTDCS) and measuring their current-voltage characteristic curves at low temperatures ranging from 300 K down to 50 K. A mechanism of carrier transport in the fabricated heterojunctions was investigated based on thermionic emission theory. According to this theory, the ideality factor was calculated from the slope of the linear part of the forward lnJ-V plot. The ideality factor was 1.12 at 300 K and increased to 1.99 at 225 K. The estimated ideality factor implied that a recombination process was the predominant mechanism of carrier transport. When the temperatures decreased below 225 K, the ideality factor was estimated to be higher than two and parameter A was estimated to be constant. The obtained results implied that the mechanism of carrier transport was governed by a trap-assisted multi-step tunneling process. At high forward bias voltage, the predominant mechanism of carrier transport was changed into a space charge limit current process.

Barrier properties and current conduction mechanism for metal contacts to lightly and highly doped p-type 4H-SiC

2021 ◽  
Author(s):  
Lingqin Huang ◽  
Yue Ma ◽  
Sumin Pan ◽  
Jing Zhu ◽  
Xiaogang Gu
Keyword(s):  
Carrier Transport ◽  
Theoretical Calculations ◽  
Thermionic Emission ◽  
Barrier Properties ◽  
Emission Model ◽  
Metal Contacts ◽  
Barrier Heights ◽  
Thermionic Field Emission ◽  
Barrier Inhomogeneities ◽  
P Type

Abstract The barrier properties of Ti, Ni and Pt contact to lightly (9×1016 cm-3) and highly (9×1018 cm-3) doped p-type 4H-SiC were investigated. It is found that the barrier heights and ideality factors estimated from thermionic emission model for the lightly doped samples are non-ideal and abnormally temperature dependent. The anomalies have been successfully explained in terms of both pinch-off model and Gaussian distribution of inhomogeneous barrier heights. In addition, the evaluated homogeneous barrier heights are reasonably close to the average barrier heights from capacitance-voltage measurements. For the highly doped samples, thermionic field emission (TFE) is found to be the dominant carrier transport mechanism. The barrier heights estimated from TFE model are temperature independent. If the barrier inhomogeneities and tunneling effects are considered, the experimental results of the samples are in well agreement with the theoretical calculations.

Current Transport Mechanism of n-Type Nanocrystalline FeSi2/Intrinsic Si/p-Type Si Heterojunctions Fabricated by Facing-Targets Direct-Current Sputtering

2013 ◽  
Vol 802 ◽  
pp. 199-203 ◽  
Author(s):  
Nathaporn Promros ◽  
Suguru Funasaki ◽  
Ryūhei Iwasaki ◽  
Tsuyoshi Yoshitake
Keyword(s):  
Ideality Factor ◽  
Low Temperatures ◽  
Transport Mechanism ◽  
Carrier Transport ◽  
Thermionic Emission ◽  
Current Transport ◽  
Current Transport Mechanism ◽  
Current Voltage ◽  
P Type ◽  
Direct Current Sputtering

n-Type nanocrystalline FeSi2/intrinsic Si/p-type Si heterojunctions were successfully fabricated by FTDCS and their forward current-voltage characteristics at low temperatures were analyzed on the basis of thermionic emission theory. The analysis of J-V characteristics exhibits an increase in the ideality factor and a decrease in the barrier height at low temperatures. The values of ideality factor were estimated to be 2.26 at 300 K and 9.29 at 77 K. The temperature dependent ideality factortogether with the constant value of parameter A indicated that a trap assisted multi-step tunneling process is the dominant carrier transport mechanism in this heterojunction. At high voltages, the current transport mechanism is dominated by SCLC process.

Temperature Dependent Current-Voltage Characteristics of n-Type Nanocrystalline-FeSi2/p-Type Si Heterojunctions Fabricated by Pulsed Laser Deposition

2013 ◽  
Vol 858 ◽  
pp. 171-176
Author(s):  
Nathaporn Promros ◽  
Ryūhei Iwasaki ◽  
Suguru Funasaki ◽  
Kyohei Yamashita ◽  
Chen Li ◽  
...  
Keyword(s):  
Barrier Height ◽  
Ideality Factor ◽  
Carrier Transport ◽  
Series Resistance ◽  
Thermionic Emission ◽  
Temperature Dependent ◽  
Zero Bias ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
P Type

n-Type NC-FeSi2/p-type Si heterojunctions were successfully fabricated by PLD, and their forward current-voltage characteristics were analyzed on the basis of thermionic emission theory (TE) in the temperature range from 300 down to 77 K. With a decrease in the temperature, the ideality factor was increased while the zero-bias barrier height was decreased. The calculated values of ideality factor and barrier height were 3.07 and 0.63 eV at 300 K and 10.75 and 0.23 eV at 77 K. The large value of ideality factor indicated that a tunneling process contributes to the carrier transport mechanisms in the NC-FeSi2 films. The series resistance, which was estimated by Cheungs method, was strongly dependent on temperature. At 300 K, the value of series resistance was 12.44 Ω and it was dramatically enhanced to be 1.71× 105 Ω at 77 K.

Cost Effective Synthesis and Fabrication of Phase-Pure Kesterite Cu2-xZn1.3SnS4 P-type Absorber Layer Thin Films by Solvent Based Process Technique for Photovoltaic Solar Energy Applications

2018 ◽  
Vol 7 (4) ◽  
pp. 36
Author(s):  
B. Khadambari ◽  
S. S. Bhattacharya
Keyword(s):  
Solar Energy ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Absorber Layer ◽  
Window Layer ◽  
Energy Applications ◽  
Process Technique ◽  
Absorber Material ◽  
Effective Synthesis ◽  
P Type

Solar has become one of the fastest growing renewable energy sources. With the push towards sustainability it is an excellent solution to resolve the issue of our diminishing finite resources. Alternative photovoltaic systems are of much importance to utilize solar energy efficiently. The Cu-chalcopyrite compounds CuInS2 and CuInSe2 and their alloys provide absorber material of high absorption coefficients of the order of 105 cm-1. Cu2ZnSnS4 (CZTS) is more promising material for photovoltaic applications as Zn and Sn are abundant materials of earth’s crust. Further, the preparation of CZTS-ink facilitates the production of flexible solar cells. The device can be designed with Al doped ZnO as the front contact, n-type window layer (e.g. intrinsic ZnO); an n-type thin film buffer layer (e.g. CdS) and a p-type CZTS absorber layer with Molybdenum (Mo) substrate as back contact. In this study, CZTS films were synthesized by a non-vaccum solvent based process technique from a molecular-ink using a non toxic eco-friendly solvent dimethyl sulfoxide (DMSO). The deposited CZTS films were optimized and characterized by XRD, UV-visible spectroscopy and SEM.

Temperature dependency and carrier transport mechanisms of Ti/p-type InP Schottky rectifiers

2010 ◽  
Vol 504 (1) ◽  
pp. 146-150 ◽  
Author(s):  
V. Janardhanam ◽  
Hoon-Ki Lee ◽  
Kyu-Hwan Shim ◽  
Hyo-Bong Hong ◽  
Soo-Hyung Lee ◽  
...  
Keyword(s):  
Carrier Transport ◽  
Temperature Dependency ◽  
Transport Mechanisms ◽  
Schottky Rectifiers ◽  
P Type
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