Prospects of e-beam evaporated molybdenum oxide as a hole transport layer for perovskite solar cells

Perovskite solar cells have emerged as one of the most efficient and low cost technology for delivering of solar electricity due to their exceptional optical and electrical properties. Commercialization of the perovskite solar cells is, however, limited because of the higher cost and environmentally sensitive organic hole transport materials such as spiro-OMETAD and PEDOT:PSS. In this study, an empirical simulation was performed using Solar Cell Capacitance Simulator software to explore MoOx thin film as an alternative hole transport material for perovskite solar cells. In the simulation, properties of MoOx thin films deposited by electron beam evaporation technique from high purity (99.99%) MoO3 pellets at different substrate temperatures (room temperature, 100 °C and 200 °C) were used as input parameters. The films were highly transparent (>80%) and have low surface roughness (≤ 2 nm) with bandgap energy ranging between 3.75 eV to 3.45 eV. Device simulation has shown that the MoOx deposited at room temperature can work in both the regular and inverted structures of the perovskite solar cell with a promising efficiency of 18.25%. Manufacturing of the full device is planned in order to utilize the MoOx as an alternative hole transport material for improved performance, good stability and low cost of the perovskite solar cell

Evaluation of the effect of mouthwash containing black mulberry (Morus nigra L.) fruit juice for treatment of gingivitis

Background and objectives: Black mulberry (Morus nigra L.) is well-known for its nutritional and medicinal values. Traditionally, the fruits have been used for treatment of mouth and throat inflammations. The aim of this study was evaluation of the effect of black mulberry fruit juice for treatment of gingivitis. Methods: The study was a randomized double blind clinical trial on 60 patients with acute gingivitis. The selected people were non-smokers and without any systemic diseases. The patients were divided into 3 groups; group 1: black mulberry juice (BMJ) 1% mouthwash, group 2: chlorhexidine 0.2% mouthwash and group 3: normal saline (NS) mouthwash. All patients were instructed to use 10 mL of the mouthwash twice daily (morning and evening) after brushing and flossing. Plaque and gingival indices in the first visit and then at 1 and 2 months after the beginning of treatment were evaluated and analyzed. Results: BMJ mouthwash caused a significant decrease in plaque and gingival indices compared to NS group. There was no significant difference between BMJ and chlorhexidine groups. The total anthocyanin content of the juice was 284.76±8.33 mg cyanidin3-glucoside equivalents per 100 g dried juice. Conclusion: The fruit juice of M. nigra can be considered for treatment of oral inflammatory diseases

Accurate Calibration of Power Measurements from Internal Power Sensors on NVIDIA Jetson Devices

Power efficiency is a crucial consideration for embedded systems design, particularly in the field of edge computing and IoT devices. This study aims to calibrate the power measurements obtained from the built-in sensors of NVIDIA Jetson devices, facilitating the collection of reliable and precise power consumption data in real-time. To achieve this goal, accurate power readings are obtained using external hardware, and a regression model is proposed to map the sensor measurements to the true power values. Our results provide insights into the accuracy and reliability of the built-in power sensors for various Jetson edge boards and highlight the importance of calibrating their internal power readings. In detail, internal sensors underestimate the actual power by up to 50% in most cases, but this calibration reduces the error to within ±3%. By making the internal sensor data usable for precise online assessment of power and energy figures, the regression models presented in this paper have practical applications, for both practitioners and researchers, in accurately designing energy-efficient and autonomous edge services

Optimization of Mo/Cr bilayer back contacts for thin-film solar cells

© 2018 Khoshsirat et al. Molybdenum (Mo) is the most commonly used material as back contact in thin-film solar cells. Adhesion of Mo film to soda-lime glass (SLG) substrate is crucial to the performance of solar cells. In this study, an optimized bilayer structure made of a thin layer of Mo on an ultra-thin chromium (Cr) adhesion layer is used as the back contact for a copper zinc tin sulfide (CZTS) thin-film solar cell on a SLG substrate. DC magnetron sputtering is used for deposition of Mo and Cr films. The conductivity of Mo/Cr bilayer films, their microstructure and surface morphology are studied at different deposition powers and working pressures. Good adhesion to the SLG substrate has been achieved by means of an ultra-thin Cr layer under the Mo layer. By optimizing the deposition conditions we achieved low surface roughness, high optical reflectance and low sheet resistivity while we could decrease the back contact thickness to 600 nm. That is two thirds to half of the thickness that is currently being used for bilayer and single layer back contact for thin-film solar cells. We demonstrate the excellent properties of Mo/Cr bilayer as back contact of a CZTS solar cell