Research database

Earth is inhabited by an energy hungry human society. The Sun, with a global radiation at the ground level of more than 1 kW/m2, is our largest source of energy. However, the 45% of the total radiation is in the near infrared (NIR) and is not absorbed by most of the photovoltaic materials. PAIDEIA focuses on two main advantages to exploit aiming to enhance the capacity of solar to energy conversion: i) plasmon assisted hot carrier extraction from NIR active unconventional plasmonic materials; ii) linewidth narrowing in plasmonic nanoparticle films that enhance the lifetime of hot carriers and ultimately enhance the efficiency of light driven carrier extraction. By combining both concepts we aim to produce a solar cell device that functions in the NIR reaching efficiencies of up to 10%. Thus, a tandem solar cell that combines the conventional power conversion efficiency of a commercial Sì solar cell (~ 20%) with the new PAIDEIA based device reaching a total power conversion efficiency of 30% by extending the solar energy range that is converted to the full spectral range delivered by the Sun. PAIDEIA has a deeply fundamental character and a high impact on solar to energy conversion technology. Instead of metals that work mostly in the visible, we will use doped semiconductor nanocrystals (DSNCs) as hot electron extraction materials, with absorption tunability between 800 nm to 4000 nm. Indeed, while solar cells based on hot electron extraction with noble metals, as gold or silver, work in the visible range and, consequently, directly compete with the well established silicon solar cells, the cells based on DSNCs will harvest the NIR radiation of the Sun, playing a complementary role with Si solar cells. We will exploit three different innovative systems: i) DSNC/wide band gap semiconductor junctions; ii) DSNCs coupled with 2D quantum materials, as transition metal dichalcogenides and phosphorene, that possess a high absorption cross section when they are atomically thin, to build DSNC/2D material ultrathin junctions; iii) DSNC/semiconductor bulk hetero-Schottky junctions, where a proper semiconductor will form a randomized network with DSNCs to maximize the interface among the two materials.