Die Steninen Mittelamerikas (Col., Staph.)(Schlu f)

Volume: 29Start Page: 617End Page: 64

XXXI. — The Subfamily Steninae, as represented in Northern Sarawak

Volume: 3Start Page: 453End Page: 46

Ostpal\ue4arktische Steninen (Col. Staph)

Volume: 30Start Page: 559End Page: 57

Ion-implanted laser-annealed p+ and n+ regions. A potential solution for industrially feasible high-efficiency n-type interdigitated back-contact solar cells

The main challenge for interdigitated back-contact (IBC) solar cells is to reduce the fabrication complexity, which consists of multiple high-temperature processing and patterning steps. Patterned ion implantation has been proposed to simplify the manufacture of IBC solar cells, and the annealing of boron and phosphorus implanted areas is still a problem for the application. In this study, a new method consisting of laser annealing and a subsequent low-temperature oxidation (LA&OX) has been developed to co-anneal boron implanted p+ and phosphorus implanted n+ regions by a single step. We found that an additional laser annealing before oxidation could improve the electrical properties of boron-implanted p+ regions effectively; however, it has almost no effect on the phosphorus-implanted n+ regions. An industrially feasible IBC solar cell fabrication technology has been proposed based on the patterned ion implantation and LA&OX processing. The main fabrication steps of the IBC solar cell could be reduced to ten steps, and only one high-temperature oxidation step is required. As-designed IBC cell shows a potential efficiency higher than 23% according to simulations with the experimental parameters

Iron related solar cell instability: Imaging analysis and impact on cell performance

Iron is an omnipresent and efficiency-limiting impurity in p-type silicon solar cells. A very useful technique to detect the interstitial iron concentration in boron doped silicon is based on carrier lifetime measurements at two metastable states of iron, namely interstitial and bound to boron. We present a further development of this technique which images the iron concentration not only on wafer level but also on finished solar cells and in this way enables the most direct access to the impact of interstitial iron on cell performance. With the help of this method we reveal that remaining iron in solar cells may be responsible for significantly unstable current-voltage characteristic under illumination. Recommendations for stable cell measurements even for cells containing a significant concentration of iron are given