Investigating Reliability Attributes of Silicon Photovoltaic Cells: An Overview
Reliability attributes are being developed on a wide variety of advanced single-crystal silicon solar cells. Two separate investigations: cell-contact integrity (metal-to-silicon adherence), and cracked cells identified with fracture-strength-reducing flaws are discussed. In the cell-contact-integrity investigation, analysis of contact pull-strength data shows that cell types made with different metalization technologies, i.e., vacuum, plated, screen-printed and soldered, have appreciably different reliability attributes. In the second investigation, fracture strength was measured using Czochralskli wafers and cells taken at various stages of processing and differences were noted. Fracture strength, which is believed to be governed by flaws introduced during wafer sawing, was observed to improve (increase) after chemical polishing and other process steps that tend to remove surface and edge flaws.
Contact integrity testing of stress-tested silicon terrestrial solar cells
A test procedure was developed and applied to terrestrial silicon solar cells in order to determine the effect of accelerated environmental and time-temperature aging on metal contact integrity. Quantities of cells of four different manufacturers were given the contact integrity test after being subjected to accelerated stress tests that included forward bias-temperature, thermal cycle and thermal shock, power cycle, and bias-temperature humidity tests at two temperature-humidity levels. Significant effects due to certain stress tests were found for some cell types. It is concluded that cells fabricated using plated nickel/solder metallization showed significantly more serious contact integrity degradation than silver-metallized cells.
The mark of sexual preference in the interpretation of texts: preface to a homosexual reading.
Since reading is an interaction or confrontation between the reader and the text-an interaction that depends upon the background and perspectives of the reader as well as on the text being read-we can assume that the dynamics of sexuality and sexual object choice will influence how readers ascribe meaning to literary texts. In fact, although other aspects of our identities come into play when we read, sexual identity is unique and central because of the role that it plays in the creation of subjectivity. Specifically, male homosexuality informs and structures the reading of texts. But what does it be a homosexual reader or to effectuate a homosexual reading of a particular text?