State of the Art and Perspectives of Inorganic Photovoltaics

Abstract

In the last decade, the fast increase of the global energy consumption, mainly related to the strong economic growth in the Far East, and the progressive depletion of the fossil fuels induced a run-up in the world oil price. Both these economic concerns and the growing global pollution pointed out that a transition toward renewable energies is mandatory. Among renewables, the conversion of sunlight into electricity by photovoltaic (PV) devices is a reliable choice to cope the growing energy consumption, due to the huge potentially extractable power (up to 120000 TW). The most important classes of inorganic PV devices developed in the last sixty years will be reviewed in this paper, in order to depict the state of the art of the technologies which dominate the PV market. Some novel concepts which could have an important role in the future of PV will be also described.

Silicon film deposition on crystalline, sintered and powder substrates using an inline optical processing CVD system

“…Four strategies can be highlighted: (i) kerf-free wafering processes [1,2], (ii) ribbon technologies [3][4][5][6], (iii) upgraded metallurgical grade Si [7], and iv) thin-films grown over a substrate [3,4,8,9]. Thin-films R&D has focused its competitiveness on nondetachable silicon films on cheap substrates or detachable films on high-quality silicon substrates [10].…”

Dye‐Sensitized Heterogeneous Photocatalysts for Green Redox Reactions

“…[69] In apparent contrast with the above reports highlighting the importance of a robust dye attachment to TiO 2 , Cai, Peng et al reported an efficient photocatalytic system based on a binuclear Ru complex loosely attached to the semiconductor. [70] The efficiency of dye [Ru 2 (bpy) 4 Surprisingly, the authors found that the sensitizer devoid of carboxylic anchoring groups provided a much better performance compared to the other two species when used in the pres-ence of TEOA as SED, even when a simple physical mixture with P25 was used ( Figure 9b). Such observation was attributed to the specific nature of the sensitizer: on the one hand, the presence of two ruthenium centers allowed an improved charge separation upon photoexcitation thanks to an "antenna effect", driven by a metal-to-metal charge transfer (MMCT) process; on the other, the loose attachment to TiO 2 via hydroxyl groups established a dynamic adsorption equilibrium (attachment/detachment of the oxidized sensitizer), minimizing charge recombination compared to the strongly attached dyes (Figure 9c).…”

“…A different kind of dye was used by Liu, Su and co-workers, who introduced four light-harvesting units in a calix [4]arene scaffold, decorated with four -OH groups (HO-TPA, Figure 18) required to create a very strong binding with TiO 2 . [100] ReP (Figure 20) was chosen as the catalyst and anchored to the HO-TPA/TiO 2 system, while a mixture of BIH and TEOA was found to be the best performing combination of SEDs.…”

“…In this context, harvesting of solar radiation appears particularly promising, since sunlight is abundant, widely distributed on Earth's surface, virtually inexhaustible and free. Accordingly, along several decades, massive efforts have been dedicated to the discovery of new materials for the efficient conversion of solar light into electric current by means of different kinds of photovoltaic (PV) devices . Despite the great successes achieved in this field, it is worth noting that currently electricity demand does not represent the largest portion of global energy needs, which is instead constituted by fuels, mostly used for transportation and heating .…”

“…Accordingly, along several decades, massive efforts have been dedicated to the discovery of new materials for the efficient conversion of solar light into electric current by means of different kinds of photovoltaic (PV) devices. [3][4][5][6][7] Despite the great successes achieved in this field, it is worth noting that currently electricity demand does not represent the largest portion of global energy needs, which is instead constituted by fuels, mostly used for transportation and heating. [8] Furthermore, solar radiation is inherently intermittent and its intensity and duration are affected by several different factors (geographical location, seasonal variability, weather).…”