This tutorial provides fundamental physics and technologies to develop tandem solar cells. Characterization techniques of tandem solar cells are also introduced.

The fundamentals of solar cells, recombination of carriers through defects, and characterization using optical and electrical techniques will be presented. This lecture will be based on chalcogenide compound thin film solar cells, but will cover a wide range of topics.

Perovskite solar cells (PSCs) have emerged as a revolutionary technology in photovoltaics due to their excellent properties and potential for efficient solar energy conversion. Single-junction PSCs have demonstrated impressive power conversion efficiency exceeding 26% in laboratory. Due to their tunable bandgap property, perovskite-based tandem solar cells, hold potential for achieving efficiency beyond the single-junction Shockley-Queisser limit, which could be one of the important solutions for the next generation of solar cells. Although remaining challenges, ongoing research endeavors continue to advance PSCs towards commercial feasibility.

Electric vehicles (EVs) are already suppressing the global oil consumption, and expected to further bring down the global CO₂ emission. The situation of rapidly declining costs and improving charge speeds of batteries, and how they are changing our ways to supply renewable power globally, will be briefly introduced in ~ 100 slides.

Various degradation phenomena induced by hygrothermal, thermal-cycle, mechanical, UV irradiation, and high-voltage stresses are observed by outdoor exposure or indoor acceleration test. Key technologies for reliable photovoltaic modules are presented based on degradation mechanism. Required reliability for photovoltaic modules employed in novel applications such as building- or vehicle-integrated photovoltaics, agro-photovoltaics, and floating photovoltaics is also discussed.

As the large amount of photovoltaic power generation expands in Japan, various problems (safety, confliction with local communities, etc.) have occurred. This tutorial will introduce recent policy trends due to measures these issues.
In addition, photovoltaic power generation is expected to further introduction and be long-term infrastructure power supply more in order to achieve carbon neutrality by 2050. This tutorial also will introduce the policies and future system technologies due to achieve goals.