Cu2ZnSnSe4 thin film solar cells are usually fabricated on a soda lime glass substrate with a molybdenum (Mo) back contact. It is suspected that degradation in electrical performance occurs due to the formation of a barrier between the absorber and Mo back contact. To overcome such degradation, Titanium Nitride (TiN), Titanium Tungsten (TiW), Chromium (Cr), Titanium (Ti) and Aluminum (Al)

Cu2ZnSi(S,Se)4 and Cu2Si(S,Se)3 are potential materials to obtain cost effective high band gap absorbers for tandem thin film solar cell devices. A method to synthesize Cu2SiS3, Cu2SiSe3and Cu2ZnSiSe4thin film absorbers is proposed. This method is based on a multistep process, using sequential deposition and annealing processes. X-ray diffraction analysis performed on the final thin films have

In this paper, we investigate the performance of an ALOHA random access wireless network consisting of nodes with and without RF energy harvesting capability. We develop and analyze a Markov model for the system when nodes with RF energy harvesting capability are infinitely backlogged. Our results indicate that the network throughput is improved when the conventional nodes are underloaded. On the

We have investigated different nonidealities in Cu2ZnSnSe4-CdS-ZnO solar cells with 9.7% conversion efficiency, in order to determine what is limiting the efficiency of these devices. Several nonidealities could be observed. A barrier of about 300 meV is present for electron flow at the absorber-buffer heterojunction leading to a strong crossover behavior between dark and illuminated current

This paper introduces a memristor based redundant binary adder for canonic signed digit code, that coding eliminates the carry and provides a carry-free addition. The proposed binary adder circuit tries to achieve high addition speed that is independent on the length of the data using the accumulation property of a Nano-element called a memristor. The general block diagram of the proposed circuit

This paper introduces a memristor based N-bits redundant binary adder architecture for canonic signed digit code CSDC as a step towards memristor based multilevel ALU. New possible solutions for multi-level logic designs can be established by utilizing the memristor dynamics as a basis in the circuit realization. The proposed memristor-based redundant binary adder circuit tries to achieve the

Modification of the absorber surface properties by Cd2+ treatment (Cd2+ partial electrolyte) results in the following: formation of Cd(OH)2 on the absorber surface, deposition of thinner chemical bath-deposited CdS buffer layer, and a smaller space charge region. The impact on electrical performances is as follows: decrease of the series resistance (RS), increase of the fill factor, increase of

Recently, mem-elements have become fundamental in the circuit theory through promising potential applications based on the built-in memory-properties of these elements. In this paper, the mathematical analysis of the memcapacitor model is derived and the effect of different voltage excitation signals is studied for the linear dopant model. General closed form expressions and analyses are presented

This paper introduces two voltage-controlled memristor-based reactance-less oscillators with analytical and circuit simulations. Two different topologies which are R-M and M-R are discussed as a function of the reference voltage where the generalized formulas of the oscillation frequency and conditions for oscillation for each topology are derived. The effect of the reference voltage on the

Novel chitosan-ZnO composites have been synthesized as luminescent taggants for cellulosic materials. The synthesized chitosan-ZnO nanospheres (CS-ZnO NS), chitosan-ZnO-oleic acid quantum dots (CS-ZnO-oleic QD) and chitosan-ZnO-oleic acid:Eu3+ doped nanorods (CS-ZnO-oleic:Eu3+ NR) were characterized by X-ray diffraction, photoluminescence spectroscopy, FTIR spectroscopy and transmission electron