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The typical absorber layer thickness to the solar cells is 3–5 µm as well as the controlled copper doping is very promising for CdTe thin films and concerned solar cell devices to achieve low resistivity and ohmic contacts as well. In this study, we report the physical properties of e-beam developed CdTe:Cu films (0.55 µm) with an impact of thermal annealing. The structural study revealed that films have preferential growth along (1 1 1) zinc blende cubic plane, and crystallinity improved with annealing. The electrical current is found to increase with voltage and decrease with annealing which revealed nearly ohmic behavior and shrinking in electrical conductivity. Films surface have deep valley and hill like topography while higher roughness is observed for 300 °C annealed films. Transmission spectra showed lower transmittance in the whole visible region and optimum band gap (1.58 eV) is estimated for 300 °C annealed films. Our study exposes that 300 °C annealed CdTe:Cu films have a preference to become a suitable candidate for absorber layer functions.

The possibility of maximum transmittance at lower thickness of light transmitting ZnS layer and its optimization by air-annealing as an alternative to hazardous and expensive CdS is reported in this communication in order to achieve better buffer layer for solar cells. Thin films of ZnS were deposited using e-beam evaporation on glass and ITO substrates and subjected to air-annealing followed by characterizations for physical properties. XRD patterns revealed amorphous behavior which transformed into cubic (111) plane with change of substrate and annealing whereas surface topography reveals hill and deep valley like structures. Optimal transmittance of maximum 95% in visible region, direct band gap of 3.38 eV and maximum electrical conductivity were observed for 200 °C annealed films. The study refers that films annealed at 200 °C are claimed to be suitable for buffer layer applications.

The exceptional need of potential Cd-free buffer layer in thin film solar cell devices motivated us to study the role of post-deposition Hydrogen annealing for the optimization of physical properties of ZnS thin films. The deposited films of thickness 200 nm were hydrogenated within the flow rate range of 50.0–150.0 sccm at 200 °C. XRD analysis revealed transformation of amorphous into cubic phase with maximum crystallinity at 150.0 sccm for films deposited on glass substrate while into wurtzite structure for films on ITO substrate with enhanced crystallinity. A mixed phase (cubic and hexagonal) at 150.0 sccm also appeared. Electrical behaviour (I–V) exhibits ohmic nature with maximum carrier concentration at 100.0 sccm. The blue shift in absorption edge and maximum of 95% transmittance were recorded in the visible region with optical energy band gap of 3.41 eV at 150.0 sccm. The reduction in surface roughness is observed in surface topographical analysis while the photoluminescence (PL) study indicated a sharp peak at 2.95 eV with strongest emission for 150.0 sccm attributed to reduction of defects at interstitial sites and passivation of grain boundaries. These results are useful to understand the Hydrogen related impurities in ZnS films and the improvement caused by hydrogenation to physical properties suited for buffer layer in solar cells.

The polycrystalline thin films comprise grain boundaries which act as recombination centres that may be passivated by chloride treatment. The conventional CdS and CdCl2 are very famous as optical window and chloride treatment in solar cells respectively, while both are expensive and severely mutagenic. Therefore in this paper, we report MgCl2 treatment on ZnS films, which is a low-cost noncarcinogenic alternative. ZnS thin films were grown on glass and ITO substrates using e-beam evaporation method, treated with MgCl2 and further thermally annealed to optimize physical properties. Films are found amorphous in nature having transmittance of about 95% and band gap increased up to 3.95 eV with annealing. Surface roughness is increased and proper ohmic behaviour is found for 300 °C treated films and EDS pattern ensured the deposition of ZnS films. To minimize the environmental risk and to reduce cost, our results exhibit that CdS optical window may be easily substituted by MgCl2 treated ZnS buffer layer.

Manual methods used during anaesthesia, to decide and deliver the quantity of drug, required significant effort from the clinical standpoint not guaranteeing an optimal performance. Delivering adequate anaesthesia requires precise automation in anaesthesia drug delivery system which will improve the patient safety, reduce the cost due to minimal consumption of drug and will help in early post-operative recovery. The present study discusses a fuzzy proportional-integral-derivative (fuzzy PID) based controller to suggest the change in quantity of isoflurane to be delivered to the patient, for the maintenance of the desired anaesthetic depth, as targeted by the anaesthesiologist. Depth of Hypnosis (DoH) of the patient is measured using BIS(TM) index and is used as the measured variable in the controller designed for the maintenance of anaesthesia during surgery. The fuzzy PID controller efficiently deals with the nonlinearity of physiological systems.

In this study, an EnKF-based assimilation algorithm was implemented to estimate root-zone soil moisture (RZSM) using the coupled LSP–DSSAT model during a growing season of corn. Experiments using both synthetic and field observations were conducted to understand effects of simultaneous state–parameter estimation, spatial and temporal update frequency, and forcing uncertainties on RZSM estimates. Estimating the state–parameters simultaneously with every 3-day assimilation of volumetric soil moisture (VSM) observations at 5 depths lowered the average standard deviation (ASD) and the root mean square error (RMSE) for RZSM by approximately 1.77% VSM (78%) and 2.18% VSM (93%), respectively, compared to the open-loop ASD where as estimating only states lowered the ASD by approximately 1.26% VSM (56%) and the RMSE by 1.66% VSM (71%). The synthetic case obtained RZSM estimates closer to the observations than the MicroWEX-2 case, particularly after precipitation/irrigation events. The differences in EnKF performance between MicroWEX-2 and synthetic observations may indicate other sources of errors in addition to those in parameters and forcings, such as errors in model biophysics.