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Graphical abstract The Figure (left) shows different colored SMART coating encapsulated on crystalline (c-Si) silicon solar cells and (right) 156 cm2 monocrystalline silicon solar cells with front metal contacts made using cover glass with selective reflector coatings giving red color. The front busbar demonstrates the transparency of the SMART coating on glass. Highlights • Nanophotonic coatings for colored solar modules. • The colored coatings show high transmission ∼70–80% in the solar absorption spectrum. • Proof of concept demonstrated with 5 in. crystalline solar cell with relative conversion efficiency of 70–80%. • White colored solar cell fabricated with relative conversion efficiency of 60%. • Industrially feasible low temperature fabrication technology for polymeric sheets and cover glass. Abstract In this article, we have reported a nanophotonic coating called Selectively Modulated Aesthetic Reflector Technology (SMART), which can be integrated to any matured solar cell technology to produce colored solar cells or modules. This technology has a potential significance in building integrated photovoltaics to improve aesthetics along with being commercially feasible. As a proof of concept, we have integrated this technology into crystalline silicon solar cells. Here we have used one-dimensional dielectric photonic crystals to selectively reflect the light, to realize multi-color appearances for the solar cells. Silicon Nitride (SiN) and Silicon Oxynitride (SiON) dielectric layers with varying compositions and thickness were used to fabricate these SMART coatings. The optoelectronic effects have been elucidated by spectroscopic, quantum efficiency and I-V measurements. The color perception has been quantitatively investigated using CIE (International Commission on Illumination) 1931 chromaticity diagram. The CIE color co-ordinates for the SMART coatings were (0.39, 0.32), (0.25, 0.38) and (0.20, 0.17) respectively for Red, Green and Blue (RGB) colours and (0.27, 0.29) for white. The cells show an integrated transmittance between 60 and 80% in the absorption regime of the solar cell depending on its color. The efficiency and the performance of different colored solar cells namely RGB and white have been shown on 156 cm2 cell area. The RGB colors have a relative power conversion efficiency of ∼70–80% based on different colors whereas white has a relative efficiency of 59% as compared to the standard reference silicon solar cell. This process is industrially feasible and could utilize the vertical area of buildings, which could have a significant application in urban landscaping. [ABSTRACT FROM AUTHOR]

Highlights: [•] Epitaxial BZN thin films were deposited on Al2O3 by Pulsed laser deposition. [•] This is the first report on domain matched epitaxial growth of BZN thin films. [•] The pole figure analysis gives deep insight into the structural orientation of BZN. [•] Fourier filtered TEM images of BZN–ZnO interface reveals the domain matched epitaxial growth. [•] Epitaxial BZN thin films shows higher tunability and low dielectric loss. [ABSTRACT FROM AUTHOR]

The structural, electrical and optical properties of copper–indium alloys sulphurised in H2S atmosphere have been studied by varying the thermal cycle of the sulphurisation process. Cu–In alloy prepared by elemental evaporation of copper and indium was used as the precursor for sulphurisation. The chalcopyrite CuInS2 phase was found at sulphurisation temperature as low as 250°C and single phase at sulphurisation temperature 350°C. At low sulphurisation temperature different binary phases like CuS, Cu2S, InS and In6S7 were found. Short sulphurisation time also results in secondary binary phases. The optimum sulphurisation temperature was 350°C for three hours, which resulted in single-phase p-type chalcopyrite CuInS2 films with a band gap of 1.45 eV. The dependence of processing parameters and the Cu/In ratio of the starting precursors on the electrical, optical and structural properties have also been studied. [Copyright &y& Elsevier]

Fabrication of laser fired contacts using µs-pulsed laser has been studied. In order to achieve damage free contact and low contact resistance in silicon solar cell, pulse length and number of pulses of the laser have been varied and it was observed that 11 µs, 100 pulses provide a good ohmic contact. The contact diameter is as small as 30 µm. As the passivation layer for the p-type rear surface, a-SiON x :H and a-SiON x :H/a-SiN x :H have been explored and these PECVD deposited layers provides excellent passivation leading to effective lifetime as high as 90 µs or more with the Cz wafers. Solar cells were fabricated on 12 cm 2 and 16 cm 2 area using Cz wafers with the rear side point contacts were realised by the laser firing of Al film deposited by electron-beam or thermal evaporation. On 16 cm 2 area, V oc value as high as 628 mV has been obtained after annealing at 375 °C for 20 min. However, these cells suffered from low fill factor. Finally, cells were also fabricated on 156 cm 2 area with LFC using 0.3 mm of contact pitch. Fill factor of 77.3% has been achieved with LFC metallization fraction of 0.8% at the rear surface. An efficiency of 15.8% was obtained. By avoiding the edge losses, a FF enhancement to 78.9% was observed using smaller cells of 100 cm 2 area. [ABSTRACT FROM AUTHOR]

• Perovskite nanorods synthesis by intercalation of long-chain organic cations. • Use of oleylammonium organic cation into bulk methylammonium tin-lead bromides as cations. • Poly(methyl methacrylate) encapsulated nanorods are excellent memristor active layer. SET voltage lowered to ∼ 0.5 V and ON OFF current ratios enhanced to ∼105. Stable mixed cation (tin-lead) perovskite nanorods results from intercalating long-chain organic ligand- oleylamine into perovskite 3D (CH 3 NH 3 PbBr 3) structure using the ligand-assisted re-precipitation method. A spin-coated nanorod film works as an active layer for resistive memory devices by sandwiching nanorod film between two electrodes with a switching voltage of 1.4 V. A poly(methyl methacrylate) passivated nanorod film results in better resistive memory properties by exploiting advantages of both insulating poly(methyl methacrylate) and semiconducting perovskite nanorods. The passivation enhances the stability of the device, protecting electrodes from reacting with the perovskite layer. The structure lowers the current in the high resistance state, increasing the ON OFF current ratio to ∼ 105. The device exhibits non-volatile rewritable resistive switching characteristics with a switching voltage ∼ 0.5 V. The conduction mechanism involved in the switching action is explained from the relation between current-voltage as space charge limited conduction. [ABSTRACT FROM AUTHOR]

• PEDOT: PSS-CNT composite prepared by a facile method used as HSL in c-Si solar cell. • The device performance was found to vary with the CNT wt.% in the composite film. • The junction properties were analysed using EIS measurements. • PEDOT: PSS-CNT /Si solar cell obtained an efficiency of 9.05% with a V oc of 588.6 mV. In this work, we present a simple and solution-based synthesis approach to combine the virtues of PEDOT:PSS and carbon nanotube (CNT) by developing a composite film and their application as a hole selective layer (HSL) in organic-silicon hybrid heterojunction solar cell. The heterojunction solar cell with the optimised PEDOT: PSS-CNT HSL showed a notable open-circuit voltage (V oc) of 588.6 mV, short circuit current density (J sc) of 25.3 mA/cm2 and fill factor (FF) of 60.79% yielding a photo-conversion efficiency (η) of 9.05%. The pristine PEDOT:PSS/Si device obtained an η of 6.2% with a V oc of 502 mV. The role of CNT in the charge transport mechanism and improving V oc was corroborated by employing various characterisation methods such as J-V , C-V , and electrochemical impedance spectroscopy. The composite layer induced a strong inversion layer in silicon and enhanced the device performance. The application of PEDOT:PSS-CNT composite film is not limited to c-Si solar cells, but can also be used to fabricate flexible organic and perovskite solar cells. [ABSTRACT FROM AUTHOR]

• The effect of post deposition annealing on MoOx heterojunction is evaluated. • TCO sputtering degrades Si/MoO X heterojunction, annealing recovers damage partially. • MoO X gets reduced on Si, thus its effective workfunction is lower on Si than on glass. • Si surface is highly inverted and MoO X workfunction aligns with Si valence band edge. • Solar cells with 12.8% efficiency could be fabricated without intrinsic a-Si:H. Heterojunction of molybdenum oxide with silicon is used as an effective hole collector in Si based carrier selective solar cells. Although the deposition of MoO X on Si is a low temperature process, the subsequent processes involved in the fabrication of the solar cell can impact the hole collection efficiency of Si/MoO X junction. In this manuscript we address the influence of post-deposition fabrication processes the subsequent processes involved in the fabrication of the solar cell can impact the hole collection efficiency of Si/MoO X junction. In this work we have found that the necessary annealing and sputtering steps have a degrading impact on the heterojunction. The underlying reasons are identified and widely described. Furthermore, to gain insight into the unique transport mechanism of heterojunction, a quantitative band diagram is obtained based on the empirical data (electron spectroscopy, optical and electrical measurements). The workfunction of thermally evaporated MoO X is found to be strongly substrate dependent and the electron affinity is deduced and measured to be 5.09 eV. The doping of MoO X films due to oxygen vacancies is found to be non-uniform as the oxygen content of the film decreases rapidly, from MoO X surface to Si/MoO X interface. Lastly, we report Si/MoO X heterojunction solar cells with high short circuit current of 33.9 mA/cm2, an open circuit voltage (V OC) of 585 mV, and an efficiency of 12.8%. [ABSTRACT FROM AUTHOR]