Synthesis and Characterization of Layers of CuCoZnS Based Thin Film Solar Cell and Fabrication of a Pilot Cell by Chemical Bath Deposition Technique for Clean Energy Application
PIs: Tizazu Abza (PhD) and et. al, 2019
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Executive Summary
Conducting problem-oriented research and applying the knowledge and technologies generated thereof is considered as one of the pillars in fostering the socio-economic development of Ethiopia. However, nationwide development cannot be attained by conducting fragmented disciplinary research. It demands the integration of multibackground professionals who work together to bring sound solutions for deep-rooted problems and generate knowledge and skills that aid to exploit the available resources of the nation. Therefore, a transition from fragmented research to multidisciplinary /interdisciplinary thematic research is required. Currently, most Ethiopian higher institutes are changing their research trend into this type of research. Hawassa University is doing the same starting from January 2017 (2009 G.C). This summary report is based on the three years of thematic research on the synthesis of pilot thin-film solar cells based on CuCoS, which was one of the thematic researches commenced in January 2017. More detailed analyses will be published in other reports.
This thematic research intended to generate knowledge and lay the foundation for technology transfer in solar energy/photovoltaic technology by commencing research on synthesis and characterization of unfamiliar absorber material, CuCoZnS, using a simple chemical route. The project has been partitioned into three subprojects with a final goal to fabricate a pilot CuCoZnS based thin-film solar cell.
The first subproject was dedicated to synthesizing the CuCoZnS thin films by establishing the common deposition conditions of the binary materials CuS, CoS and ZnS and tuning its properties, especially the band gap by varying the relative concentration of the metal ions. The main purpose of incorporating Zn in the films was to tune the band gap of the absorber material, CuCoZnS, in the range of 1 eV to 2 eV. This range of band gaps could be obtained by controlling the deposition conditions and the Cu to Co ratio. As a result, no Zn was incorporated in the absorber layer of the pilot thin-film solar cell. Structural, morphological, optical, and electrical properties of the binary and the ternary films were characterized by XRD, SEM, UV-VIS, and two electrical probe measurements.
The second subproject dealt with the deposition of CdS and ZnO thin films with appropriate properties to be used as the buffer and the window layers of the intended pilot CuCoS-based thin-film solar cell, respectively. Uniform and smooth aluminum-doped CdS thin films were synthesized to get n-type material to form a p-n junction with the naturally p-type CuCoS absorber material. Very adherent, uniform, smooth, and highly conductive aluminum-doped ZnO thin films that are suitable to be used as a transparent conducting oxide material were also synthesized in this same subproject.
The last but the most important subproject was stacking of each layer of the solar cell from the bottom up order: aluminum substrate as a back electrical contact, CuCoS absorber, Al:CdS buffer, and Al:ZnO transparent conducting oxides. The operation of the sample solar cell was tested by exposing direct sunlight. A 4.5 cm2 area pilot solar cell gives an open circuit voltage reading up to 370 mV and a short circuit reading of 2.6 mA at the noontime. The core works of the project were carried out in Hawassa university's physics/material science laboratory. Sample characterizations were carried out in AAU, ASTU, and abroad due to lack of equipment in our university.
The following are recommended to improve the research findings. The sputtering technique is advised to be used for coating the front and the back electrical contacts. These can improve efficiency and minimize the material cost to coat the two electrodes. Measurement of carrier concentration and mobility of these carriers is important. Detailed measurements of the cell parameters under a controlled environment are highly recommended for the prototype solar cell to fully understand its operation and commercialize it.
Cancer in Southern Ethiopia: Epidemiology, Quality of Care, Economic and Psycho-Social Burden
PIs: Dr. Achamyelesh G/Tsadik and et al. 2022
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EXECUTIVE SUMMARY
Background: Cancer is a big problem in both developed and developing countries. It has become one of the most common diseases worldwide and the second leading cause of death. That is evidenced by 3.71 million new cases and 1.93 million deaths, and the incidence of cancer is increasing because of the growth and aging of the population, as well as an increasing prevalence of established risk factors. It causes enormous morbidity and mortality in our current globe, including depression and anxiety. Hence, cancer had negative effects on the quality of life of cancer patients and increased periods of hospitalization and higher mortality rates, which causes the highest economic loss of all of the leading 15 causes of death worldwide. The economic shock includes both the loss of income and the expenses associated with health care costs. Despite the pieces of evidence, little attention was given to individual patients living with cancer. Objectives: Determine the epidemiology, quality of care, the economic and psycho-social burden of cancer in the population of southern Ethiopia.
Methods: Hospital-based cross-section study was employed. Patients' records treated with any cancer case was reviewed. All available data from the cancer registry and logbook located at a unit of oncology and pathology were reviewed. A 7-year card review was conducted to examine the trends of cancer distribution by socio-demographic characters. The trends of cancer were identified for all the patients treated at Hawassa university's comprehensive specialized hospital, by cancer type, stage of cancers, treatment modality received.
A Multi-stage sampling method was used to choose study participants. The documentation review interviewer-administered questionnaire and different measuring scales like Quality of Life Instrument (WHOQOL)-BREF and hospital anxiety, Quality of Oncology Nursing Care Scale and depression scale (HADS) were used to collect data. The collected data was cleaned, coded by Epi data version 3.1 and entered into SPSS, and analyzed using SPSS version 20.0 software. Descriptive statistics were used to describe the study subjects. Variables with a p-value < 0.25 in the bivariate analysis were further entered into the multivariate logistic regression model. Finally, in all analyses, P-value <0.05 was considered as significant and presented by adjusted odds ratio (AOR) with 95% C.I.
Result: Over a period of seven years, 2013-2019, more than 80 cancer types were identified by body site, a total of 4658 new cases were recorded in all outpatient departments and oncology ward of HURCSH. Out of this, 3002 (64.5%) cards with complete records of new cases of cancer were taken for this study. Of all, 1846(61.4%) were female, and 1159(38.6%) were male. M: F ratio is 1:1.6. Accordingly, laryngeal cancer was more common among males than females, followed by bladder cancer. Nasopharyngeal ca, Colonic and lung ca, osteosarcoma, and NHL were other common cancers in Male populations. On the other hand, out of gynecological ca, thyroid ca, and renal ca were common among females. However, the general burden of cancers was found among females more than males as the result of breast and cervical ca.
Despite 58.8% and 60.0% having depression and anxiety, respectively, the overall global health quality scale was 75.3(SD±17.1) with mean health satisfaction with high satisfaction on environmental domains. Among patients on cancer treatment, 60% perceived they have received good quality of nursing care and were satisfied by the health care service that was provided during their hospital stay. The economic burden of cancer was high, with the total cost of $209.99 was spent on average. Medication cost is the highest ($20.77 IQR=0.53-112.56) from the direct medical costs and transportation cost ($58.33 IQR=22.0-131.67) is the highest from the indirect medical costs. Furthermore, medication cost is the highest compared to all other costs spent when each type of cancer is concerned. The total out-of-pocket money incurred on inpatients was $245.16 (IQR=147.64-439.20), while for the outpatients, it was $147.37 (IQR=81.42-240.50). The patients lose about 55.99% of their average annual income. The cost balances towards the patients who came from the Oromia region irrespective of the distance and those who are inpatients. Prior information about cancer is needed in the first place, and due attention has to be given by extending the service to Oromia, and timely treatment is recommended.
Conclusion and recommendations: The incidence and trends of many cancers are highly increasing through the years. Poor screening practice and increasing risk factors due to lifestyles and aging were related to cancer's high incidence and economic burdens. Regular registration, provision of preventive care through risk reduction and screening, and vaccination for some cancer types could minimize the morbidity and mortality of cancer.