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Cost effective non-vacuum sprayed GZO layer was utilized in electrodeposited CZTS-based thin film solar cells for the first time. The thus-obtained solar device presented an appreciable conversion efficiency of 6.43%.

A novel precursor with zinc oxide (ZnO) structure was synthesized for ZnO film deposition using diethylzinc in some solvents. Non-doped ZnO films on a glass substrate were successfully grown by conventional spin coating using the nondoped novel precursor solution. Highly porous and dense ZnO thin films were obtained at 150°C using the novel precursor with chlorobenzene and toluene, respectively.Zinc oxide (ZnO) is a semiconductor having a hexagonal structure and a large band gap of 3.4 eV at room temperature (RT). Because of its attractive properties, ZnO has been investigated for use in multiple applications such as gas are attractive for ZnO thin film growth because of the avoidance of plasma-generated surface damage. An additional advantage of these methods is that the use of high vacuum is not required, leading to very low equipment cost. Furthermore, low-temperature ZnO growth processes are important for compatibility with the fabrication processes of photovoltaic devices based on advanced thin film materials such as CuInGaSe 2 . 10 Recently, photovoltaic devices based on hybrid metalorganic perovskite materials have attracted considerable attention as leading candidates for use in next-generation solar cells.11,12 Au/spiro-OMeTAD/CH 3 NH 3 PbI 3 / porous TiO 2 /dense TiO 2 /FTO/glass structure is generally used in perovskite-based solar cells.13 FTO/glass is used because high temperatures above 400°C are required for fabricating porous TiO 2 .11,12 Therefore, low-temperature growth processes for fabricating porous TiO 2 or substituting porous TiO 2 by a different material are necessary for developing flexible perovskite-based solar cells.However, it is known that because of the low thermal energy, low-temperature growth in non-vacuum processes is challenging and there have been only few reports on low-temperature growth at less than 200°C under non-vacuum conditions. Nishinaka et al. reported the low-temperature growth of ZnO at 150°C by spin coating using zinc acetylacetonate in 2-butanol.14 This resulted in a sample with a smooth surface morphology and porous structure arising from the aggregation of ZnO grains.In our previous work, 15 a non-doped ZnO film was successfully grown on a poly(ethylene terephthalate) substrate by conventional atmospheric spray pyrolysis at low temperatures using a diethylzinc (DEZ)-based solution. DEZ is a well-known metalorganic chemical vapor deposition (MOCVD) precursor for ZnO films with a boiling point of 118°C at atmospheric pressure. The samples exhibited an optical transmittance of more than 80% on an average, a rough surface, and a predominately a axis orientation as determined by optical transmittance, scanning electron microscopy (SEM), and X-ray diffraction (XRD) measurements, respectively. To expand the possible options for ZnO film deposition, we have also fabricated ZnO films at low temperatures using a spin-coating method with a simple DEZbased solution that was previously used for spray pyrolysis. 16In our previously reported DEZ solution, some ether compou...

Non‐doped and Ga‐doped ZnO film on glass substrate were successfully grown at 150 °C by conventional atmospheric spray pyrolysis using diethylzinc‐based solution. The samples had an average optical transmittance of more than 80% and were strongly a‐axis orientated according to the results of optical transmittance and X‐ray diffraction analysis, respectively. The n‐type Ga‐doped ZnO films had a low resistivity of 2.3 × 10–3 Ωcm, a carrier concentration of 1.1 × 1020 cm–3 and a mobility of 10 cm2 (Vs)–1 at an optimal Ga content of 2 at% upon UV irradiation. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The growth of (0002) orientated polycrystalline undoped and Ga-doped ZnO films by DC sputtering under Ar is described. The (0002) peak intensity decreases with increasing substrate temperature in both doped and undoped samples. The average grain sizes are very small. This indicates that ZnO films with low crystallinity are obtained at high substrate temperatures. It is deduced that surface damage can be increased by high energy plasmas of neutral Ar particles at high substrate temperatures. The average surface roughness for both undoped and Ga-doped ZnO films decreases with increasing substrate temperatures. It is deduced that energies of sputter particles decrease with increasing substrate temperatures due to collisions with Ar particles. The surface roughness corresponds well to the structure model.