High Efficiency Ultrathin CIGS Solar Cells

The global demand for renewable energy is growing rapidly. Increasing the global share of alternative sources of energy would not only bring environmental benefits, but also enhance overall energy security by diversifying energy supply. Many technology options exist nowadays to harvest the power of the sun, a sustainable energy source, and generate electricity directly from this source via the photovoltaic effect. Among them, Cu(In,Ga)Se2 (CIGS) has gained significant momentum as a possible high efficiency and low cost thin film solar cell material. The capacity to scale up any photovoltaic technology is one of the criteria that will determine its long term viability. In the case of CIGS, many manufacturers are showing the way for GW-scale production capacity. However, as CIGS technology continues to increase its share of the market, the scarcity and high price of indium will potentially affect its ability to compete with other technologies. One way to avoid this bottleneck is to reduce the importance of indium in the fabrication of the cell simply by reducing its thickness without significant efficiency loss. Reducing the thickness of CIGS thin film will not only save the material but will also lower the production time and the power needed to produce the cell. The material properties of Cu(In,Ga)Se2 thin films are different with deposition process. Many different methods to deposit Cu(In,Ga)Se2 thin film have been tried until now but Cu(In,Ga)Se2 thin films prepared by co-evaporation of elemental sources are the most successful due to the control over the sequence of evaporation of individual material. However, the co-evaporation process is a complex process and, depending on the individual sources and substrate temperature, the thin films are grown with different characteristics. The characteristics of these thin films changes with the change in the atomic percentage (at.%) of Cu, In, Ga and Se, which depends on the evaporation conditions. Among different co-evaporation techniques to grow Cu(In,Ga)Se2, 1-stage, 2-stage and 3-stage co-evaporation processes are the most successful processes. Co-evaporation process is the best technique for highly efficient CIGS solar cell but this process needs a precise control of the elemental composition in the vapor flux in order to achieve high quality material, which is not easy to obtain due to the low sticking coefficient of Selenium. One of the major concerns in Cu(In,Ga)Se2 thin film solar cell fabrication that affect significantly the cell performance during deposition is stoichiometry. CIGS with low Se samples exhibited very low Cu content, additional chalcopyrite phases, very small grain size, and poor solar cell performance. So it is very important to find the minimal selenium flux to obtain high quality Cu(In,Ga)Se2 thin film. During the deposition of ultrathin Cu(In,Ga)Se2 film with 1-stage, 2-stage and 3-stage co-evaporation processes, real time spectroscopic ellipsometry (RTSE) is implemented to study the material properties as well as to monitor the process. The deposition processed for individual layer of CIGS device are optimized to enhance the efficiency of the CIGS solar cell

Effect of different levels of phosphorus on growth and yield of Cowpea varieties in Dang, Nepal

Variety having proper response to phosphorus for proper nutrient uptake and the optimum level of phosphorus for higher  yield may be a way of increasing production and productivity in the context of Nepal. This experiment  was carried out in Lamahi Municpality, Dang district of the Province no: 5, inner terai region of Nepal during the rainy season, 2019. The objective of the experiment was to study the effect of different phosphorus level on growth and development of different varieties of cowpea. The experiment was laid out in two factorial RCBD with two varieties (Aakash and Prakash) and five phosphorus level (0 kg ha-1, 20 kg ha-1, 40 kg ha-1, 60 kg ha-1 and 80 kg ha-1). The result revealed that variety Aakash showed the significantly higher yield of fresh pod (15.99 t ha-1) and yield attributing parameters like number of leaves at 45 DAS (35.22), leaf area at 45 DAS (70.23 cm²), pod diameter (0.77 cm), total number of fresh pods per plant (44.85) than Prakash variety (yield; 12.25 t ha-1). The parameters like number of branches and pod length were not affected by the variety used. In addition, the different level of P also affects the yield of the fresh pod of different varieties. The P level 40 kg ha-1 reported highest yield of fresh pod (20.18 t ha-1 and showed significantly higher number of leaves (38.9), number of branches (23.48), plant height (88.78cm), leaf area (81.89 cm²), pod length (17.76 cm), pod diameter (0.79 cm) and total number of fresh pods per plant (55.19) whereas control produced the lowest total yield of fresh pod (8.33 t ha-1), control (30.99) and 80 kg P ha-1 (30.86) produced the least number of leaves, control produced the least number of branches (17.31), control (63.77 cm) and 80 kg P ha-1 (67.83) produced the shortest plant, 80 kg P ha-1 produced the minimum leaf area (51.09 cm2), control produced least pod length (14.3 cm), pod diameter (0.74cm), total number of fresh pods (34.29). Similarly, interaction of Aakash and phosphorus dose 40 kg ha-1 produced significantly maximum number of leaves (43.07) and total yield of fresh pods (23.33 t ha-1). The results of the experiment revealed that variety Aakash with the phosphorus level 40 kg ha-1 seems the more profitable in Terai and inner Terai condition of Nepal. However, the results need to be confirmed for other varieties used by farmers in the region

Retraction notice to “Adoption of goat production technology and its impact among rural farmers in nawalparsi district of nepal” [Jurnal Agercolere, 1(1), 1–5]

This article has been retracted: please see Jurnal Agercolere Publication Ethics (http://faperta.unisan.ac.id/jurnal/index.php/jac/ethics). This article has been retracted at the request of the Editor-in-Chief. The author has published manuscripts describing essentially the same research in more than one journal or primary publication, as follow: Aryal, M. Jaishi and A. Gaire, “Adoption of goat production technology and its impact among rural farmers of Nawalparasi district, Nepal” - Nepalese Journal of Agricultural Sciences, 2018, pp. 109–113. ref.6 url: http://www.hicast.edu.np/uploads/colleges/16/5c2a464490dbd.pdf One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.This article has been retracted: please see Jurnal Agercolere Publication Ethics (http://faperta.unisan.ac.id/jurnal/index.php/jac/ethics). This article has been retracted at the request of the Editor-in-Chief. The author has published manuscripts describing essentially the same research in more than one journal or primary publication, as follow: Aryal, M. Jaishi and A. Gaire, “Adoption of goat production technology and its impact among rural farmers of Nawalparasi district, Nepal” - Nepalese Journal of Agricultural Sciences, 2018, pp. 109–113. ref.6 url: http://www.hicast.edu.np/uploads/colleges/16/5c2a464490dbd.pdf One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

Plant protection measures to promote organic farming in Nepal: prospects and challenges

Organic farming is a production system that relies on ecosystem management rather than external agricultural inputs to sustain the health of soils, ecosystem and organisms. This needs enough organic plant protection measures and biological fertilizers by eliminating synthetic pesticides and fertilizers. An attempt was made to review current plant protection measures for organic farming in Nepal. Though some insect pests and diseases are very hard to control without the use of chemical pesticides, this is high time to produce agriculture products organically. There is ample prospect of organic production in Nepal utilizing traditional knowledge of Nepalese farmers and existing agri-biodiversity. The paper is focused on best utilization of local natural resources, indigenous knowledge and bio-control agents for plant protection in organic agriculture. The information related to organic plant protection measures are collected from various sources and are grouped. The authors have listed technologies on organic plant protection measures in Nepal and made some suggestions to improve the organic farming of the country

Adoption of Goat Production Technology and Its Impact Among Rural Farmers in Nawalparsi District of Nepal

Nayabelhani VDC of Nawalparasi district was chosen to judge the effectiveness of goat production technology supported by Heifer International Nepal. Field survey with before and after approach was employed in the study. Information obtained from Stratified random sampling technique from 90 households with structured questionnaire and was compared with the baseline data. Adoption index was calculated through scoring technique after content validation. Participatory rural appraisal for problems identification. The research revealed that the extent of adoption of scientific goat production technology after project was higher than before project (80% Vs 32%, P<0.01). Further, the average herd size after the project was slightly decreased from 6.585 to 5.677 while the kid mortality dropped from 15% to 11%. The average number of kidding in 2 years was increased from 2 to 3 and the average number of kids per kidding was increased from 1 to 2. Goats were more frequently marketed at an average age of 12 months with an average weight of 24kg after the project. Similarly, the average annual income from the goat per household was found to be almost doubled from Nrs. 8,489 to Nrs. 15,084. Predator was found to be the most serious problem out of seven identified problems

Characterization and Analysis of Ultrathin CIGS Films and Solar Cells Deposited by 3-Stage Process

In view of the large-scale utilization of Cu(In,Ga)Se2 (CIGS) solar cells for photovoltaic application, it is of interest not only to enhance the conversion efficiency but also to reduce the thickness of the CIGS absorber layer in order to reduce the cost and improve the solar cell manufacturing throughput. In situ and real-time spectroscopic ellipsometry (RTSE) has been used conjointly with ex situ characterizations to understand the properties of ultrathin CIGS films. This enables monitoring the growth process, analyzing the optical properties of the CIGS films during deposition, and extracting composition, film thickness, grain size, and surface roughness which can be corroborated with ex situ measurements. The fabricated devices were characterized using current voltage and quantum efficiency measurements and modeled using a 1-dimensional solar cell device simulator. An analysis of the diode parameters indicates that the efficiency of the thinnest cells was restricted not only by limited light absorption, as expected, but also by a low fill factor and open-circuit voltage, explained by an increased series resistance, reverse saturation current, and diode quality factor, associated with an increased trap density

Evaluation of different chemical fungicides against rice blast in field conditions

Evaluation of different fungicides against rice blast was carried out in research plot of the Agronomy farm of IAAS, Prithu Technical College, Lamahi Municpality, Dang district of the Lumbini Province, inner terai region of Nepal during June to November, 2017. The objective of the experiment was to evaluate the efficiency of different chemical fungicides against rice blast. The experiment was conducted in Randomized Complete Block Design with the use of susceptible variety ‘Mansuli’. Different fungicides like Hexaconazole 5% SC (Udaan), Propiconazole 25% EC (Tilt), Captan 70% + Hexaconazole 5% WP, Validamycin 3% L, Tricyclazole 75% WP (TRIP) and Biomycin (Kasugamycin 3% S.L.) were applied five times at weekly interval with the doses of 2mL/L of H2O, 1.5mL/L of H2O, 2g/L of H2O, 2mL/L of H2O, 2g/L of H2O and 2mL/L of H2O respectively. From the result, it was concluded that all the fungicides were effective in controlling leaf blast but Tricyclazole 75% WP (TRIP) was more effective among other fungicides and untreated control plots with least leaf blast severity (27.85%), least incidence (35.5%), least mean AUDPC (64.64%) and highest grain yield (3.93 t ha-1) followed by Biomycin. It is thus concluded that fungicide Tricyclazole 75% WP should be sprayed five times at weekly interval for the management of leaf blast in rice

Effects of integrated nutrient management in early season cauliflower production and its residual effects on soil properties

This experiment was conducted in the farmer’s field at Khajrauta, Gadhawa-4, Dang, Nepal to evaluate the effect of integrated nutrient management on growth and yield of cauliflower as well as their residual effects on soil properties. The cauliflower variety silvercup-60 was grown under eight different treatments; T1: 50% N through RDF + 50% N through FYM; T2: 50% N through RDF + 50% N through PM; T3: 50% N through RDF + 50% N through VC, T4: 50% N through RDF + 25% N through FYM + 25% N through PM; T5: 50% N through RDF + 25% N through VC + 25% N through PM; T6: 50% N through RDF + 25% N through VC + 25% N through FYM; T7: 50% N through RDF + 25% N through  VC +25% N through FYM; T8: 50% N through RDF + 50% N  through FYM,VC and poultry manure. The experiment was laid out in RCB design with three replications. The result revealed that the  highest plant height (36.40 cm), number of leaves (15), plant spread (31.72 cm), leaf area (526.5 cm2), curd weight (207.3g) and curd yield (12.85 t/ha) were found under 50% N through RDF +50% N through VC. The root length, root diameter and root density were better under all INM treatments as compared to 100% N through RDF. INM treatments showed lesser bulk density, lesser particle density, greater infiltration rate and greater organic matter content than application of 100% N through RDF. Soil total nitrogen was increased in all INM treatments while soil available phosphorus decreases in all treatments except 100% N trough RDF and 50% N through RDF +50% N through PM. Thus, farmers are suggested to apply 50% N through VC along with 50% N through RDF to increase cauliflower yield.  &nbsp

Effect of different levels of nitrogen on growth and yield of hybrid maize (Zea mays L.) varieties

Nitrogen (N) fertilizer is considered as one of the most important factors affecting growth and grain yield of hybrid maize. This study was conducted to determine the effects of different rates of nitrogen and varieties on growth and yield of hybrid maize in Lamahi Municipality, Dang, Nepal from June to October, 2019. Three levels of hybrid maize varieties (10V10, Rajkumar F1 and NMH-731) and four levels of nitrogen (160, 180, 200 and 220 kg N ha-1) were evaluated using two factorial randomized complete block design with three replications. The results showed that grain yield and yield attributing traits of hybrid maize varieties increased with the increasing level of nitrogen from 160 to 220 kg ha-1. The application of nitrogen @ 220 kg N ha-1 produced the highest grain yield (10.07 t ha-1), cob length (16.33 cm), no of rows per cob (14.97), no of grains per row (33.37), cob diameter (4.54), thousand grain weight (276.77 g), stover yield (12.91 t ha-1), biological yield (23.00 t ha-1), harvest index (43.80), gross return (NRs. 208940 ha-1), net return (NRs.104488 ha-1) and B:C ratio (2.001). The hybrid maize variety 10V10 produced the highest grain yield (9.35 t ha-1), net returns (NRs. 91740.66 ha-1) and B:C ratio (1.91) accompanied by the highest cob length (16.25 cm), and as number of grains per row (32.35) as compared to other varieties. This study suggested that maize production can be maximized by cultivating hybrid maize variety 10V10 with the use of 220 kg N ha-1 in inner Terai region of Nepal

Effect of gibberellic acid on growth and flowering attributes of African marigold (Tagetes erecta) in inner terai of Nepal

A field experiment was conducted at Bangaun, Lamahi-3, Dang, Nepal to study the effect of GA3 on growth and flowering attributes of African marigold (Tagetes erecta) in Inner Terai of Nepal. The experiment consists of three replications and 8 treatments and laid out in a randomized complete block design- consisting of various concentrations of GA3 viz. 0ppm, 50ppm, 100ppm, 150ppm, 200ppm, 250ppm, 300ppm, and 350ppm. Kolkata local variety of African marigold was tested. The study revealed that among different concentrations of GA3, 300ppm showed the tallest plant height (72.93cm) and the highest basal diameter (1.49cm). Maximum numbers of primary branches (3.11) and the greatest plant spread (32.11cm) were obtained from 250ppm; similarly, maximum numbers of secondary branches (13.80) were recorded in 350ppm. In the case of floral parameters both 100ppm and 350ppm recorded earlier days to 50% flowering (44.00 days each), days for 100% flowering was recorded almost similar in every treatment that sticks around 54 and 55 days, maximum diameter (5.370cm) of flowers were obtained from 50ppm, the greatest fresh weight (6.180g) was recorded in 350ppm, 250ppm showed a maximum number of flower per plant (104.13), similarly, a longer duration of flowering (58 days) was recorded in 300ppm. Among all treatments, the 250ppm level of GA3 was found to be most suitable in terms of production perspective