To improve the performance of PSCs, interfacing green synthesized flake like-ZnO nanostructure have been introduced between ETL/perovskite layer which reduces the recombination losses at the interface.

In this work, the pulse electrodeposition technique has been employed for the first time to deposit SnSe films from a bath containing Analar grade 50 mM tin chloride (SnCl 4 ) and 5 mM SeO 2 . The XRD profile of SnSe thin films deposited at different duty cycles indicate the peaks corresponding to SnSe. Atomic force microscopy studies indicated that the surface roughness increased from 0.5 to 1.5 nm with duty cycle. The transmission spectra exhibited interference fringes. The value of refractive index at 780 nm was 2.1, this value decreased to 1.95 with decrease of duty cycle. The room temperature resistivity increased from 0.1 to 10 Xcm with decrease of duty cycle. Photo electrochemical cell studies were made using the films deposited at different duty cycles. For duty cycles greater than 15% photo output was observed. For a film deposited at 50% duty cycle, an open circuit voltage of 0.55 V and a short circuit current density of 5.0 mA cm -2 at 60 mW cm -2 illumination. Capacitance voltage measurements indicated V fb = 0.67 V (SCE) and p type, carrier density = 6.98 9 10 16 cm -3 .

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Copper Indium Selenide (CIS) thin films were pulse electrodeposited at room temperature and at different duty cycles in the range of 6 – 50 %. Deposition current density was kept constant at 5 ma cm-2 in the present work. The total deposition time was 60 min. The precursors used were AR grade 0.3 M of each CuCl2 and InCl3, along with 0.2 M of SeO2. Thickness of the films estimated by Mitutoyo surface profilometer varied in the range of 0.8 to 1.2 μm with increase of duty cycle. XRD patterns of CIS films deposited at different duty cycles exhibit the chalcopyrite structure. Composition of the films indicated Cu/In ratio is greater than 1. Optical absorption studies indicated a direct energy band gap of 0.95 eV. Surface morphology of the films indicated that the grain size increased from 15 nm to 40 nm as the duty cycle increased. It is observed that as the duty cycle increases, the resistvity increases from 1.0 ohm cm to 10 ohm cm. The films were used as photoelectrodes in 0.5 M polysulphide redox electrolyte (0.5 M each Na2S, NaOH, S). At 60 mW cm-2, an open circuit voltage of 0.465 V and short circuit current density of 3.87 mA cm-2 were observed for the films deposited at 50 % duty cycle.

In this work, the pulse electrode position technique has been emeployed for the first time to deposit SnSe films. SnSe films were deposited by the pulse electrodeposition technique at room temperature from a bath containing Analar grade 50 mM tin chloride (SnCI4) and 5 mM Se02. The deposition potential was maintained as -0.9V (SCE). Tin oxide coated glass substrates (5.0 ohmsl sq) was used as the substrate. The duty cycle was varied in the range of 6 -50 %. The XRD profile of SnSe thin films deposited at different duty cycles indicate the peaks corresponding to SnSe. Atomic force microscopy studies indicated that the surface roughness increased from 0.5 nm to 1.5 nm. The transmission spectra exhibited interference fringes. The value of refractive index at 780 nm was 2.1, this value decreased to 1.95 with decrease of duty cycle. The room temperature resistivity increased from 0.1 ohm cm to 10 ohm cm with decrease of duty cycle. Photoelectrochemical cell studies were made using the films deposited at different duty cycles. For duty cycles greater than 15 % photo output was observed. For a film deposited at 50 % duty cycle, an open circuit voltage of 0.55 V and a short circuit current density of 5.0 rnA cm-2 at 60 mW cm-2 illumination. Capacitance voltage measurements indicated Vfb = 0.67 V (SCE) and p type, carrier density = 6.98 x 10161 cm3.The IV-VI compounds, tin selenide (SnSe) has received considerable attention due to its applications in a variety of devices. SnSe thin films have been deposited by different methods like vacuum evaporation [1], flash evaporation [2], hot wall epitaxy [3], reactive evaporation [4], electrodeposition [5], laser ablation [6], chemical bath deposition (CBD) [7] and electrochemical atomic layer epitaxy (ECALE) [8] to study various physical properties. The decisive requirements for the efficient performance of the devices are compositional uniformity and crystallinity. Further, the technique adopted should be simple and cost effective. Every technique has associated with it, its own merits and demerits. In this investigation, SnSe films were deposited for the first time using the pulse electrodeposition technique. 978-1-4673-0074-2/11/$26.00 @2011 IEEE 232 II.EXPERIMENT AL METHODS SnSe films were deposited by the pulse electrodepsoition technique at room temperature from a bath containing Analar grade 50 mM tin chloride (SnCI4) and 5 ruM SeOz. The deposition potential was maintained as -0.9V (SCE). Tin oxide coated glass substrates (5.0 ohms/ sq) was used as the substrate. The duty cycle was varied in the range of 6 -50 %. Thickness of the films measured by surface profilometer increased from 500 nm to 1000 nm as the duty cycle increased from 6 % to 50 %. Structural, optical, electrical and photoelectrochemical (PEC) properties of the films were studied. For PEC studies 1M polysulphide was used as the redox electrolyte. III. RESULTS AND DISCUSSIONThe XRD patterns of SnSe thin films (Fig. 1 ), deposited at different duty cycles indicate the peaks around 2e = 30° corresponding to (111...