Achim Kimmerle was born in Tettnang on November 1st 1983 and went to Rupert-Ness-Gymnasium Wangen.
During his studies in physics at the Albert-Ludwigs-University Freiburg and the Universidad de Sevilla as well as several employments at Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg he gained experiences in photovoltaic technology. He finished his studies at the ISE with a diploma thesis about the development and characterisation of emitters for industrial crystalline high efficiency silicon solar cells under supervision of Prof. R. Eicke Weber in 2011. Subsequently he continued working as a research assistant on the development and optimisation of such highly doped surfaces. After two month parental holidays due to the birth of his son on August 1st 2011 he re-joined Fraunhofer ISE to start his PhD project.
Short description of the doctoral thesis:
"Development and characterisation of back-junction and locally contacted solar cells with aluminium emitter"
A way to continue reducing costs in photovoltaic energy conversion is to transfer high efficiency solar cell concepts to industrial production in combination with new and potentially cheap module technologies. To avoid shading of the front side metallisation and to simplify module assembly back contacted solar cells are well suited. Highest conversion efficiencies of industrial solar cells are presently reached with solar cell concepts where the highly doped regions and the metal contacts are located on the rear in interdigitated structures. On large solar cells these metal fingers increase in length and therefore the electrical loss increases limiting the efficiency of the solar cell. Thus a new design of the rear of back-contact-back-junction solar cells is a possibility to increase the efficiency of large area solar cells.
In the PhD project a back-contact-back-junction solar cell is developed using exclusively industrial available technology. The lateral current transport may be realised cost effectively on module level enabling to reduce metal consumption of the solar cell and to reach the scalability of the cell area to increase productivity. For further optimisation of the rear of the solar cell analytical models are developed and verified by numerical simulation as well as experimental. The local emitter formation and its contact should be realised with cost effective screen printed aluminium.
Diffused Surfaces for High Efficiency Silicon Solar Cells Process Development, Characterization, and Modeling