Case Study of San Francisco\u27s Juvenile Probation Department\u27s Community Service Program

The following cost/benefit case study researches the San Francisco Juvenile Probation Department\u27s alternative sentencing Community Service Program. The CSP offers nonviolent, criminally charged youth the opportunity to perform community service at various nonprofit organizations in lieu of incarceration in juvenile hall. This study highlights the benefits received as well as the associated costs incurred by juvenile offenders and nonprofit organizations as a result of their participation in the Community Service Program. Suggestions for further research and possible improvements to the program are discussed after the case study findings and results are presented. For the case study, current participants or recent graduates of the program received correspondence inviting them to participate in a one-on-one interview to discuss their experience in the Community Service Program. The San Francisco Juvenile Probation Department provided names and contact information of qualified juvenile offenders. The department also extended information regarding the nonprofit organizations eligible for participation and willing to accommodate the juvenile offenders with their imposed community service sentence. Interviews with the nonprofit organizations determined various benefits the juvenile offenders could gain by completing their sentenced community service hours. The staff and administrators explained the goals of the organization, the different services the youth could perform, and ways the organization aimed to help educate the youth with job skills and social maturation. Associated costs the nonprofit organizations experienced with program administration and participation were also discussed during the interviews. The individual interviews with the juvenile offenders addressed the assigned tasks the youth performed and the perceptions they had regarding the nonprofit organizations and how they benefited from participation in the Community Service Program. The youth were also encouraged to describe areas in which they had the opportunity to learn and grow. Information from all the interviews was compiled and reported, offering statistical information on the case study participants, as well as qualitative interpretation of the data. Analysis of this case study information along with the information provided by the San Francisco Juvenile Probation Department suggests areas for program improvement and further research

Inline Bulk-lifetime Prediction on as-cut Multicrystalline Silicon Wafers

AbstractSolar cell production using multicrystalline silicon is rife with uncertainties about material quality and its impact on subsequent processing steps. However, inline electrical metrology can provide predictive information about bulk silicon quality before processing resources are applied, allowing later metrology to focus on process control. In this work, we show an industrial algorithm which enables bulk lifetime prediction in as-cut multicrystalline wafers, agnostic of wafer origin, using an inline Quasi-Steady-State Photoconductance (QSSPC) measurement setup from Sinton Instruments. In addition, we demonstrate a robust method to extract emitter saturation current density from post-diffusion wafer measurements. Finally, we extend the use of inline QSSPC with a corrected doping measurement that utilizes the theory of grain-boundary potential barriers to interpret excess conductance

High Resolution inline Topography of Iron in p-Doped Multicrystalline Bricks by MDP

AbstractThe iron density is one crucial parameter to verify the quality of the material. Brick measurements enable to check the material quality right at the beginning of the production line. This paper presents contact less high resolution inline topographic measurements of the iron density in multicrystalline silicon bricks by MDP (microwave detected photoconductivity). The measurement procedure is fully automatic and takes less than 5min a brick. The data obtained were compared to QSSPC (quasi steady state photoconductivity) measurements, however, with a loss in spatial resolution. Furthermore, passivated wafers were prepared from the bricks after the measurements and investigated individually. The consistency of all the data is remarkable

Detailed Performance Loss Analysis of Silicon Solar Cells using High-Throughput Metrology Methods

In this work, novel, high-throughput metrology methods are used to perform a detailed performance loss analysis of approximately 400 industrial crystalline silicon solar cells, all coming from the same production line. The characterization sequence includes a non-destructive transfer length method (TLM) measurement technique featuring circular TLM structures hidden within the busbar region of the cells. It also includes a very fast external quantum efficiency and reflectance measurement technique. More traditional measurements, like illuminated current-voltage, Suns-VOC, and photoluminescence imaging are also used to carry out the loss analysis. The variance of the individual loss parameters and their impact on cell performance are investigated and quantified for this large group of industrial solar cells. Some important correlations between the measured loss parameters are found. The nature of these distributions and correlations provide important insights about loss mechanisms in a cell and help prioritize efforts to optimize the performance of the production line.Comment: 5 pages, 6 figures, conferenc

Impact Of Ozone-Based Cleaning On Surface Recombination With Different Passivation Materials

In this work, the impact of different ozone-based cleaning processes on the level of surface passivation achieved is determined and compared against the RCA cleaning processes. Two different passivation materials are used in this study, including hydrogenated amorphous silicon and silicon nitride plasma enhanced chemical vapor deposition (PECVD). Photoconductance measurements and calibrated photoluminescence imaging are used to evaluate the level of passivation achieved and spatial uniformity for the different cleaning processes