• Energy Research

Abstract Ge quantum dots (QDs) have been applied to increase the internal quantum efficiency (IQE) of a photodetector up to 1500% at 400 nm and are expected to benefit the performance of solar cells. Ge QDs have been successfully prepared on silicon-based solar cells using plasma enhanced chemical vapor deposition (PECVD) at temperature lower than 300 °C. By adjusting the deposition time, RF power and H2-plasma treatment time, the Ge QDs are optimized for obtaining the highest solar cell efficiency. It is found that the quantum efficiency of the solar cells has been significantly improved by the presence of Ge QDs, particularly in the long wavelength range (>600 nm). As a result, the short-circuit current density (Jsc) is increased by 3.3%, and, consequently, the solar cell efficiency is increased.

Abstract Ge quantum dots (QDs) have been applied to increase the internal quantum efficiency (IQE) of a photodetector up to 1500% at 400 nm and are expected to benefit the performance of solar cells. Ge QDs have been successfully prepared on silicon-based solar cells using plasma enhanced chemical vapor deposition (PECVD) at temperature lower than 300 °C. By adjusting the deposition time, RF power and H2-plasma treatment time, the Ge QDs are optimized for obtaining the highest solar cell efficiency. It is found that the quantum efficiency of the solar cells has been significantly improved by the presence of Ge QDs, particularly in the long wavelength range (>600 nm). As a result, the short-circuit current density (Jsc) is increased by 3.3%, and, consequently, the solar cell efficiency is increased.

Abstract Ge quantum dots (QDs) have been applied to increase the internal quantum efficiency (IQE) of photodetector up to 1500% at the 400 nm and are expected to benefit the performance of solar cell. We have successfully prepared Ge-QDs using plasma enhanced chemical vapor deposition (PECVD) that is fully compatible with the solar cell deposition process. Transmission electron microscope (TEM) and Atomic force microscope (AFM) images show that the QDs are ∼14 nm in diameter. By adjusting deposition time, as well as H 2 dilution ratio and H 2 -plasma treatment time, the Ge-QDs are optimized for the highest solar cell efficiency. It is found that the IQE is significantly improved, particularly for long wavelength spectrum (λ > 500 nm), resulting in increased short circuit current density (Jsc) by 8.31% and increased solar cell efficiency.

Abstract Ge quantum dots (QDs) have been applied to increase the internal quantum efficiency (IQE) of photodetector up to 1500% at the 400 nm and are expected to benefit the performance of solar cell. We have successfully prepared Ge-QDs using plasma enhanced chemical vapor deposition (PECVD) that is fully compatible with the solar cell deposition process. Transmission electron microscope (TEM) and Atomic force microscope (AFM) images show that the QDs are ∼14 nm in diameter. By adjusting deposition time, as well as H 2 dilution ratio and H 2 -plasma treatment time, the Ge-QDs are optimized for the highest solar cell efficiency. It is found that the IQE is significantly improved, particularly for long wavelength spectrum (λ > 500 nm), resulting in increased short circuit current density (Jsc) by 8.31% and increased solar cell efficiency.

It is known that the properly textured ZnO film can increase light-scattering and therefore improves light-trapping inside the solar cells, resulting in increased J(sc) value and consequently solar cell efficiency. Using a low cost solution-based electrochemical deposition, we have developed a ZnO thin film deposition process that offers fine-control of crystal orientation, surface morphology and texture by tuning an additive concentration. Using the optimized textured ZnO films, we have achieved superior light trapping performance especially in long wavelength spectrum (lambda > 610 nm) comparing to the vacuum sputtered ZnO. Using single junction a-SiGe:H and multi-junction a-Si:H/a-SiGe:H/a-SiGe:H thin film solar cells, high quantum efficiency (current density) and solar cell efficiencies are attained. It demonstrates that the low cost electrochemical ZnO deposition is an effective method to prepare high quality ZnO film for solar cells. (C) 2014 Elsevier B.V. All rights reserved.

It is known that the properly textured ZnO film can increase light-scattering and therefore improves light-trapping inside the solar cells, resulting in increased J(sc) value and consequently solar cell efficiency. Using a low cost solution-based electrochemical deposition, we have developed a ZnO thin film deposition process that offers fine-control of crystal orientation, surface morphology and texture by tuning an additive concentration. Using the optimized textured ZnO films, we have achieved superior light trapping performance especially in long wavelength spectrum (lambda > 610 nm) comparing to the vacuum sputtered ZnO. Using single junction a-SiGe:H and multi-junction a-Si:H/a-SiGe:H/a-SiGe:H thin film solar cells, high quantum efficiency (current density) and solar cell efficiencies are attained. It demonstrates that the low cost electrochemical ZnO deposition is an effective method to prepare high quality ZnO film for solar cells. (C) 2014 Elsevier B.V. All rights reserved.

Abstract The effect of transparent conductive oxide (TCO) on the performance of compact-layer free perovskite solar cells has been investigated. The results show that the perovskite film formation, charge transfer and charge recombination are affected by the TCO layer. All common TCOs, including ITO, FTO and AZO, show some beneficial and detrimental characters for solar cell application. Finally, the compact-layer free perovskite solar cells based on them show similar performance.

Abstract The effect of transparent conductive oxide (TCO) on the performance of compact-layer free perovskite solar cells has been investigated. The results show that the perovskite film formation, charge transfer and charge recombination are affected by the TCO layer. All common TCOs, including ITO, FTO and AZO, show some beneficial and detrimental characters for solar cell application. Finally, the compact-layer free perovskite solar cells based on them show similar performance.

Cs+doping into 2D (BA)2(MA)3Pb4I13perovskites boosts power conversion efficiency (PCE) to 13.7% and yields superior humidity and thermal stability.