[concept and design by Treesha Runnells [concept and design by Lars Muller [concept and design by Lars Muller] concept and design by fjodor gejko [concept and design, Federica Sala]. Principle and design of solar cells [concept and design:] Pepin van Roojen. [concept and text by Donald Lemke Concept and Design by Oscar Riera Ojeda [concept and text by Donald Lemke]