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In the past several years, CH₃NH₃PbI₃ perovskite material has been extensively evaluated as an absorber layer of perovskite solar cells due to its excellent structural and optical properties, and greater than 22% conversion efficiency. However, improvement and future commercialization of solar cells based on CH₃NH₃PbI₃ encountered restrictions due to toxicity and instability of the lead element. Recently, studies on properties of lead-free and mixture of lead with other cations perovskite thin films as light absorber materials have been reported. The purpose of this paper was the fabrication of CH₃NH₃Sn₁-xPbxI₃ thin films with different SnI₂ concentrations in ambient condition, and study on the structural, morphological, optical, and photovoltaic performance of the studied solar cells. The X-ray diffraction studies revealed the formation of both CH₃NH₃PbI₃ and CH₃NH₃SnI₃ phases with increasing the Sn concentration, and improvement in crystallinity and morphology was also observed. All perovskite layers had a relatively high absorption coefficient >104 cm⁻¹ in the visible wavelengths, and the bandgap values varied in the range from 1.46 to 1.63 eV. Perovskite solar cells based on these thin films have been fabricated, and device performance was investigated. Results showed that photo-conversion efficiency (PCE) for the pure CH₃NH₃PbI₃sample was 1.20%. With adding SnI₂, PCE was increased to 4.48%.

In this work, the author mixed tin and lead with different percentages in the perovskite thin film. Also, the preparation of these layers and also other layers to fabricate solar cells based on them were conducted in an open and non-glove box environment. Finally, the effect of [Sn/Pb] ratio in the CH₃NH₃Sn₁-xPbxI₃ layers on the structural, morphological, optical, electrical and photovoltaic performance have been investigated.

CH₃NH₃Sn₁-xPbxI₃ (x = 0.0, 0.25, 0.50, 0.75, 1.0) perovskite thin films have been grown by a spin-coating technique. It was found that as tin concentration increases, the X-ray diffraction and FESEM images studies revealed the formation of both CH₃NH₃PbI₃ and CH₃NH₃SnI₃ phases, and improvement in crystallinity, and morphology; all thin films had high absorption coefficient values close to 104 cm⁻¹ in the visible region, and the direct optical bandgap in the layers decreases from 1.63 eV in pure CH₃NH₃SnI₃ to 1.46 eV for CH₃NH₃Sn0.0.25Pb0.75I3 samples; all thin films had p-type conductivity, and mobility and carrier density increased; perovskite solar cells based on these thin films have been fabricated, and device performance was investigated. Results showed that photo-conversion efficiency (PCE) for the pure CH₃NH₃PbI₃sample was 1.20%. With adding SnI2, PCE was increased to 4.48%.

The preparation method seems to be interesting as it is in an ambient environment without the protection of nitrogen or argon gas.

The purpose of this paper is to identify green envelope building components of residential buildings applicable under hot and humid climates and to analyze the effect of these components on building value.

The authors place an emphasis on green envelope components that influence building value and which are derived based on their integration into a building envelope structure that is applicable under hot and humid climates. This is performed through identification of green benefits of each green envelope component based on literature reviews and in relation to green criteria listed by the Malaysia Green Building Index (GBI). Consequently, a quantitative analysis has been conducted to determine the effect of these green envelope components on building value by means of a questionnaire distribution among 550 property valuation practitioners in Malaysia. However, in order to certify respondents’ credibility, the authors analyzed questionnaires answered by property valuation practitioners with experience in green valuation.

The findings show that there are ten green envelope components currently certified under GBI Malaysia and applicable for hot and humid climates. There are three green envelope components that can increase property values, specifically: solar photovoltaic, green living wall and green roof. However, eight of the green envelope components have no effect on building value.

Due to the relative immaturity of the green building market in Malaysia, the authors were unable to analyze the actual percentage of increment on building value as conveyed by each green envelope component.

This paper aims to provide understanding of the effect of individual green envelope components on building value rather than merely the value of green buildings in general. It proves that green building envelope components do in fact contribute to an increase in green building values. As the green building market in Malaysia is still in its infancy, this study is significant in that it prepares the Malaysian green building market to attain a new level by providing valuation practitioners with awareness of green building values and new knowledge concerning the effect of individual green components on building values. Hence, it is anticipated that this study can assist property valuation practitioners in conducting valuations of green buildings in the future.

The purpose of this paper is to investigate the chemical, optical and photovoltaic properties of titanium dioxide/reduced graphene oxide (TiO₂/rGO) photoanodes immersed in natural Roselle and synthetic (N719) dyes for dye-sensitized solar cell (DSSC) application.

TiO₂ mixed with rGO were doctor-bladed on fluorine doped tin oxide (FTO) glass substrate. The chemical and optical properties of TiO₂/rGO photoanodes immersed in Roselle and N719 dyes were characterized using Fourier-transformed infrared (FTIR) and ultraviolet–visible (UV–vis) spectroscopies, respectively. The DSSC’s photovoltaic performances were tested using Visiontec Solar I-V tester at standard illumination of AM1.5 and irradiance level of 100 mW/cm².

The presence of anthocyanin dye from Roselle flower was detected at 604 nm and 718 nm. TiO₂/rGO+Roselle dye sample revealed the smallest energy gap of 0.17 eV for ease of electron movement from valence band to conduction band. The TiO₂/rGO-based DSSC fabricated with Roselle dye had a power conversion efficiency, ƞ of 0.743 per cent higher than TiO₂/rGO photoanode sensitized with N719 dye (0.334 per cent). The obtained J-V curves were analyzed by a single-diode model of Lambert W-function and manual optimization to determine the internal electrical parameters of the DSSC. The average and uncertainty values of J_sc and ƞ were evaluated at different R_sh range of 1362 Ω to 32 k Ω.

R_s values were kept constant during optimization work.

New ideality factor of TiO₂/rGO-based DSSC was re-determined around 0.9995.

The purpose of this paper is to study the optical and electrical characteristics of a single-junction solar cell based on a green-colour dye vanadyl 2,9,16, 23-tetraphenoxy-29H, 31H-phthalocyanine (VOPcPhO). The use of soluble vanadyl phthalocyanine derivative makes it very attractive for photovoltaic applications due to its tunable properties and high solubility.

A photoactive layer of VOPcPhO has been sandwiched between indium tin oxide (ITO) and aluminium (Al) electrodes to produce a ITO/PEDOT:PSS/VOPcPhO/Al photovoltaic device. The VOPcPhO thin film is deposited by a simple spin coating technique. To obtain the optimal thickness for the solar cell device, different thicknesses of the photoactive layer, achieved by manipulating the spin rate, have been investigated.

The device exhibited photovoltaic effect with the values of Jsc, Voc and FF equal to 5.26 × 10-6 A/cm2, 0.621 V and 0.33, respectively. The electronic parameters of the cell have been obtained from the analysis of current-voltage characteristics measured in dark. The values of ideality factor and barrier height were found to be 2.69 and 0.416 eV, respectively. The optical examination showed that the material is sensitive to light in the UV region between 270 nm and 410 nm, as well as in the visible spectrum within the range of 630 nm and 750 nm.

The solar cell based on a single layer of vanadyl phthalocyanine derivative results in low efficiency, which can be enhanced by introducing a variety of donor materials to form bulk heterojunction solar cells.

The spin coating technique provides a simple, less expensive and effective approach for preparing thin films.

A novel thin-film, single-junction organic solar cell, fabricated by using VOPcPhO, has been investigated for the first time ever. The vanadyl phthalocyanine derivative together with a donor material will have potential application for improved efficiency of the solar cells.

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

The purpose of this paper is to study assembling parameters in dye-sensitised solar cells (DSSCs) performance. For this end, 3a,7a-dihydroxy-5ß-cholanic acid (cheno) are selected as anti-aggregation agent and two solutions, namely, tetrabutyl ammonium iodide and (PMII)IL used as electrolyte.

A series of organic dyes were selected using N-substituents carbazole as electron donor group and acrylic acid and cyanoacrylic acid as electron acceptor groups. Absorption properties of purified dyes were studied in solution and on photoelectrode substrate. DSSCs were prepared in the presence of anti-aggregation agent and different electrolyte to determine the photovoltaic performance of each dyes.

The results showed that all organic dyes form J-aggregation on the photoanode substrate in the absence of anti-aggregation agent and the amounts of aggregation were reduced in the presence of anti-aggregation agent. DSSCs were fabricated in the presence of anti-aggregation agent. The photovoltaic properties were improved using tetrabutyl ammonium iodide as electrolyte. The maximum power conversion efficiency was achieved for D12 in the presence of cheno and tetrabutyl ammonium iodide as anti-aggregation agent and electrolyte, respectively.

Organic dye attracts more and more attention due to low cost, facile route synthesis and less hazardous.

The effect of anti-aggregation agent and electrolyte on DSSCs performance was investigated for the first time.

The purpose of this paper is to demonstrate the influence of annealing treatment on the photovoltaic properties of the solar cell based on ITO/PEDOT:PSS/ZnO:P3HT/Ag.

The influence of the annealing temperature and time on the P3HT/ZnO interface morphology and the ITO/PEDOT:PSS/ZnO:P3HT/Ag solar cell performance was discussed. The morphology and the current‐voltage (J‐V) characteristics were investigated by atomic force morphology (AFM) and solar simulator with an AM 1.5 G filter under an irradiation intensity of 100 mW cm⁻². The light intensity was calibrated using a standard silicon photovoltaic solar cell.

The photovoltaic performances were found to have been greatly enhanced by an annealing treatment at 145°C for 30 min.

The paper demonstrates that the annealing treatments play a crucial role in improving the morphology and J‐V performance of the ITO/PEDOT:PSS/ZnO:P3HT/Ag solar cell.

The purpose of this paper is to study the substituent effect in dye-sensitized solar cells’ (DSSCs) performance. For this end, three new metal organic dyes with DPA structure were synthesized. For investigation of the substituent effect, two different anchoring groups, namely, 1,3-dioxo-1Hbenz[de]isoquinolin-2(3H)-yl)benzenesulfonamides and 1,8-naphthalimide, were used.

Three organic dyes based on azo were selected, which contain various electron donor groups. Absorption properties of purified dyes were studied in solution and on photoelectrode (TiO₂ and Z_nO) substrate. DSSCs were prepared to determine the photovoltaic performance of each photosensitizer.

The results showed that all organic dyes form J-aggregation on the photoanode substrate. Cyclic voltammetry results for all organic dyes ensured an energetically permissible and thermodynamically favorable charge transfer throughout the continuous cycle of photo-electric conversion. The results illustrate conversion efficiencies of cells based on solution Dyes 1, 2 and 3 and TiO₂ as 3.44, 4.71 and 4.82 per cent, respectively. The conversion efficiencies of cells based on solution Dye 1, 2 and 3 and Z_nO are 3.21, 4.09 and 4.14 per cent, respectively.

In this study, the development of effect of assembling materials, offering improved photovoltaic properties.

Organic dye attracts more and more attention because of its low-cost, facile route synthesis and less-hazardous properties.

To the best of the authors’ knowledge, the effect of anchoring agent and nanostructure on DSSCs performance was investigated for the first time.

Dye-sensitised solar cells (DSSCs) have attracted a great deal of interest. Dye molecules are key materials in DSSCs that produce electrons. This study reports on synthesis of the organic dyes and investigation their performance in DSSCs.

A series of new organic dyes were prepared using double rhodanine as the fundamental electron-acceptor group and aldehydes with varying substituents as the electron-donor groups. These dyes were first purified and then characterised by analytical techniques. DSSCs were fabricated to determine the photovoltaic behaviour and conversion efficiency of each individual dye.

Results demonstrated that all the dyes form j-type aggregates on the nano TiO₂. All dyes in DSSC structure show suitable power conversion efficiency, and Dye 5 due to presence of OCH₃ and OiPr presents maximum conversion efficiency.

In the search for high-efficiency organic dyes for DSSCs, development of new materials offering optimised photochemical stabilities as well as suitable optical and electrical properties is importance.

Organic dyes as photosensitisers are interesting due to low cost, relatively facile dye synthesis and capability of easy molecular tailoring.

A series of new organic metal-free dyes were prepared as sensitisers for DSSCs for the first time.

The purpose of this paper is to introduce four new organic dyes based on naphthalimide for dye-sensitized solar cells (DSSCs).

Four new dyes based on naphthalimide with substitutions of amine and acetylamine in position C4 were designed in conjugation with substituted carbazole as donor–acceptor (D-A) architecture. The absorption and emission characteristics of the prepared dyes were evaluated in H₂O, DMF and their mixture (DMF:H₂O = 1:1). The feasibility of electron transfer in the DSSCs structure and energy levels were evaluated using electrochemical and density functional theory, which confirm the use of dyes in the DSSCs structure. The DSSCs were prepared using an individual strategy and their optical properties were investigated under the light of AM 1.5.

The prepared dyes exhibit orange color with strong emission at λem = 530–570 nm due to charge transfer with a positive solvatochromic effect. The efficiency of DSSCs based on Dye1-4 1 is: 3.69%, 3.71%, 4.69% and 4.76%. Therefore, the power efficiency increases by about 29 % in the presence of acetylamine group.

The design of new structures of organic dyes should be accompanied by the development of optical and electrical properties. In other words, in addition to the continuous production of electrons, efficient dyes must also be resistant to light to increase the life of the device.

Organic dyes play a key role in the production of electrons in the DSSCs structure. The engineering of these structures and the introduction of widely used but low cost types can play an important role in the development of clean energy production.

The application of organic dyes based on naphthalimide was evaluated in the DSSCs structure and its photovoltaic properties were investigated.