Efficient organic photovoltaic cells (OPV) often contain highly reactive low-work-function calcium electron-collecting electrodes. In this work, efficient OPV are demonstrated in which calcium electrodes were avoided by depositing a thin... more
Efficient organic photovoltaic cells (OPV) often contain highly reactive low-work-function calcium electron-collecting electrodes. In this work, efficient OPV are demonstrated in which calcium electrodes were avoided by depositing a thin layer of the amine-containing nonconjugated polymer, polyethylenimine (PEIE), between the photoactive organic semiconductor layer and stable metal electrodes such as aluminum, silver, or gold. Devices with structure ITO/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/poly(3-hexylthiophene):indene-C60-bis-adduct (P3HT:ICBA)/PEIE/Al demonstrated overall photovoltaic device performance comparable to devices containing calcium electron-collecting electrodes, ITO/PEDOT:PSS/P3HT:ICBA/Ca/Al, with open-circuit voltage of 775±6 mV, short-circuit current density of 9.1±0.5 mA cm(-2), fill factor of 0.65±0.01, and power conversion efficiency of 4.6±0.3%, averaged over 5 devices at 1 sun.
The power output performance of a photovoltaic (PV) module decreases as the temperature increases. The increase in module temperature above the standard test conditions (25 ⁰C) could reduce the average power output by at least 0.2% for... more
The power output performance of a photovoltaic (PV) module decreases as the temperature increases. The increase in module temperature above the standard test conditions (25 ⁰C) could reduce the average power output by at least 0.2% for each 1 ⁰C rise. Hence, keeping the module temperature low is necessary for PV systems exposed to high solar irradiance throughout the year. Therefore, this study aims to experimentally analyse the eletctrical performance of passively cooled PV modules in the tropics. The developed cooling approach consists of rectangular plate fins made of aluminum 6061, attached to the rear surface of tedlar layer. The results indicated that the average module temperature reduction of 3.25 ⁰C was observed under outdoor exposures. As a result, the heat sink improved the overall power output up to 14.2%. As the PV performances are site-dependent, these findings are beneficial as it provides a thorough explanation of fin heat sink behavior under long-term field exposures of tropics.
Ternary metal chalcogenides such as CuInS<sub>2</sub> offer new opportunities to design quantum dot solar cells (QDSC). Chemically synthesized CuInS<sub>2</sub> quantum dots (particle diameter, 2.6 nm) have been... more
Ternary metal chalcogenides such as CuInS<sub>2</sub> offer new opportunities to design quantum dot solar cells (QDSC). Chemically synthesized CuInS<sub>2</sub> quantum dots (particle diameter, 2.6 nm) have been successfully deposited within the mesoscopic TiO<sub>2</sub> film using electrophoretic deposition (150 V cm<sup>–1</sup> dc field). The primary photoinduced process of electron injection from excited CuInS<sub>2</sub> into TiO<sub>2</sub> occurs with a rate constant of 5.75 × 10<sup>11</sup> s<sup>–1</sup>. The TiO<sub>2</sub>/CuInS<sub>2</sub> films are photoactive and produce anodic photocurrent with a power conversion efficiency of 1.14%. Capping the TiO<sub>2</sub>/CuInS<sub>2</sub> film with a CdS layer decreases the interfacial charge recombination and thus offers further improvement in the power conversion efficiency (3.91%)....
Efficient organic photovoltaic cells (OPV) often contain highly reactive low-work-function calcium electron-collecting electrodes. In this work, efficient OPV are demonstrated in which calcium electrodes were avoided by depositing a thin... more
Efficient organic photovoltaic cells (OPV) often contain highly reactive low-work-function calcium electron-collecting electrodes. In this work, efficient OPV are demonstrated in which calcium electrodes were avoided by depositing a thin layer of the amine-containing nonconjugated polymer, polyethylenimine (PEIE), between the photoactive organic semiconductor layer and stable metal electrodes such as aluminum, silver, or gold. Devices with structure ITO/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/poly(3-hexylthiophene):indene-C60-bis-adduct (P3HT:ICBA)/PEIE/Al demonstrated overall photovoltaic device performance comparable to devices containing calcium electron-collecting electrodes, ITO/PEDOT:PSS/P3HT:ICBA/Ca/Al, with open-circuit voltage of 775±6 mV, short-circuit current density of 9.1±0.5 mA cm(-2), fill factor of 0.65±0.01, and power conversion efficiency of 4.6±0.3%, averaged over 5 devices at 1 sun.
