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This paper presents an experimental investigation of photovoltaic (PV) properties in heterostructures consisting of indium oxide and amorphous silicon thin films, grown on a single crystalline p-type silicon and polyimide flexible substrates. Both thin films: In₂O₃ and a-Si were deposited by magnetron sputtering. Such heterostructure thin film systems are attractive because of their ability to convert solar energy into electrical one. Grown Heterostructures films were treated by simultaneous influence of an electron beam and high energetic photons with energy more than 1.5 eV in the so called vacuum photo-thermal processing (VPP).

Silicon samples of 100 Ω/sq and 45 Ω/sq were selected as substrates. Thin films deposition was done in argon atmosphere by DC magnetron sputtering.

It is shown that:

Open circuit voltage of the proposed structure may reach up to ~ 0.35 V,

Short circuit current was of no more then 10-7 A,

Polyimide materials may be used as substrates for PV thin film deposition structures,

VPP dramatically varies the photovoltaic properties of the heterostructure

This study aims to carry out the deposition of zinc sulfide (ZnS) thick films on glass and silicon (100) substrates using radio frequency (RF) magnetron sputtering method at different powers. Film structure has been analyzed by X-ray diffraction (XRD); the patterns showed that the films possesses a cubic structure with (111) preferred orientation. Photoluminance (PL) intensity of the films has been related to the crystallinity, which is varied with the power.

Scanning electron microscope (SEM) images have been used to discover the films’ morphology. The stoichiometry has been confirmed by energy dispersive X-ray spectroscopy (EDX) analysis. MicroRaman spectroscopy has been used to validate the film structure. Gas-sensing studies were carried out by means of a static gas chamber to sense acetone, ethanol, methanol, H₂O and NH₃ vapor in air ambient.

ZnS has a stoichiometric and cubic structure. The band gaps and photoluminance intensity of the films are correlated with the crystallinity, which is varied with the power. The EDX analysis approved the stoichiometry of the prepared films. Acetone, ethanol, humidity (H₂O), methanol and NH₃ vapor gases were used to justify the sensing properties at 25°C of the thickest ZnS film.

High-quality ZnS films have been obtained at different powers without annealing. Gases sensing properties at 25°C are justified for deposited ZnS films using acetone, ethanol, humidity (H₂O), methanol and NH₃ vapor gases. It reveals good response for NH₃ and humidity vapors at room temperature; the sensing functioning at this temperature was attractive in recent research.

This paper aims to develop a low-cost hot-point which can facilitate the conductivity type of N-type and P-type zinc oxide (ZnO) films. In this study, a diode was made out of the N-type and P-type ZnO films, and current-voltage (I-V) characteristic measurements were conducted.

A low-cost hot-point probe consists of a soldering iron station, digital multimeter and a pair of probes. The setup is adopted to identify N-type and P-type ZnO films. In particular, P-type films have been deployed for the first time.

Hot-point probe setup has been successfully developed. Measurements of N-type films give a positive voltage reading, whereas P-type films give a negative voltage reading. The measured voltage dominates at 1 per cent for N-type Ga and at 15 per cent for P-type Na. I-V characteristics of the fabricated diode showed a similar trend to the conventional diode.

N-type has been often attempted. However, P-type has rarely been attempted because of the self-compensation effect in ZnO. There is a need to verify the conductivity type of ZnO films, especially P-type, as P-type films are not stable. The hot-point probe setup serves as a quick means to verify P-type ZnO films.

To the best of the authors’ understanding, this verification tool was developed and deployed to verify the N-type and P-type ZnO films. The P-type films are coated on top of the N-type films for diode I-V measurements.

The purpose of this study is to show in power-voltage curve, a unique maximum power point (MPP) is existed which has the maximum power.

This paper presents a MPP tracker algorithm for a standalone system includes DC-DC buck converter and battery storage.

By using this algorithm, the maximum available power is achieved and simultaneously, the battery is charged and also protected against overcharge and discharge. The operation of the proposed algorithm is evaluated in with Proteus software to be sure that it can be implemented in microcontroller in reality.

The simulations results show that the proposed algorithm is able to detect the MPP under different irradiations. Moreover, the battery is charged during the day by PV and protected against overcharge and discharge.