Progress in development of graded bandgap thin film solar cells with electroplated materials

Photovoltaic devices are developed mainly based on p-n or p-i-n type device structures, and these devices can utilise only a fraction of the solar spectrum. In order to further improve device parameters and move towards low-cost and high-efficiency next generation solar cells, device architectures capable of harvesting all photons available should be designed and developed. One such architecture is the fully graded bandgap device structure as proposed recently based on both n-type and p-type window layers. These designs have been experimentally tested using well researched GaAs/AlGaAs system producing impressive device parameters of open circuit voltage (Voc) ~1175 mV and fill factor (FF) ~0.85. The devices have also been experimentally tested for the evidence of impurity photovoltaic (PV) effect and impact ionisation taking place within the same device. Since these structures have been experimentally proved with a well-established semiconductor, the effort has been focussed on developing these devices using low-cost and scalable electroplated semiconductors, in order to minimise manufacturing cost. This paper reviews and summarises the work carried out during the past decade on this subject. Graded bandgap devices produced using only two or three electroplated semiconductor layers have been explored and their conversion efficiencies have gradually increased from 10.0%, through 12.8% to 15.3% for different structures. While the work is progressing along this line, the paper summarises the achievements to date

Malaria Diagnosis And Treatment Practices By Patent And Proprietary Medicine Vendors In Bauchi Metropolis, Bauchi State in North Eastern Nigeria

Malaria is one of the leading causes of morbidity and mortality in Nigeria with about 50% of the population having at least an episode of clinical malaria each year. Patent medicine vendors are the first and most common source of malaria treatment in Nigeria. This study assessed malaria diagnosis and treatment practices by Patent and Proprietary Medicine Vendors (PPMVs) in Bauchi metropolis, Bauchi L.G.A., Bauchi State, Nigeria. This study was a cross sectional analytical study involving PPMVs in Bauchi metropolis. A total of 396 PPMVs were recruited into the study. The data was collected using 40 items questionnaire and were analyzed with frequencies, percentages and chi-square. The hypotheses postulated were tested at 0.05 level of significance. The data was analyzed by using SPSS Version 16.0.Respondents consisted of 253 (63.9%) health professionals (HPs) and 143 (36.15) non professionals (NHPs). About two third of the respondents; 99 (69.2%) among HPs and NHPs 88(61.3%) have good knowledge about malaria transmission. Only few respondents used Rapid Diagnostic Test (RDT) in identifying malaria; 12 (8.7%) among NHPs and 22 (12.6%) among HPs. The difference is not statistically significant (P-value 0.217). Moreover, 121 (47.8%) and 48 (33.6%) for both NHPs and HPs respectively reported lack of skills as the reason for not using RDT. Majority of the respondents are still dispensing Chloroquine (CQ) for malaria with 68.4% and 69.2% among NHPs and HPs respectively. The used of RDT by the respondent is poor. There is need to train PPMVs on current national policy onmalaria, especially malaria identification using RDT kits and used of Artemisinin –based Combination Therapy (ACT) in treatment of malaria. The RDT kits should also be made available.Keywords: Malaria, Diagnosis, RDT, Patent Medicine Vendors, Bauchi metropolis