Conversion Efficiency

J Nondestruct Eval (2010) 29: 38–42 DOI 10.1007/s10921-010-0063-7 Acoustic Properties of Selected Tropical Wood Species Yahya Sedik · Sinin Hamdan · Ismail Jusoh · Mahbub Hasan Published online: 12 February 2010 © Springer Science+Business Media, LLC 2010 ...

Thin films of CdS, deposited by chemical bath deposition (CBD) onto films of fluorine-doped tin oxide/glass (glass/FTO) substrates were prepared and investigated for photoelectrochemical conversion (PEC) of light into electricity. Knowing the hazardous nature of CdS, the focal theme of this work was to modify the electrodes by simple economic ways to maximize their conversion efficiency and minimize their degradation under PEC conditions. This was to avoid leaching out of hazardous Cd2+ ions. Different parameters have been investigated for this purpose. Multi-deposition preparation, redox couple, and electrode etching affected electrode PEC characteristics. Consistent with earlier literature, annealing the electrode enhanced its conversion efficiency and stability. On the other hand, effect of cooling rate of pre-annealed CdS electrodes, prepared by CBD, on their PEC characteristics has been investigated here for the first time. Controlling the cooling rate was one major factor that affected CdS surface morphology, conversion efficiency and stability under PEC conditions. The major recommendation coming out here is that PEC characteristics of CdS thin film electrodes can be significantly enhanced by pre-annealing the electrode at ∼250 °C followed by its slow cooling.

In photovoltaics, research is aiming to investigate new materials able to push the efficiency limit for solar cells towards the highest values without increasing the fabrication cost. This paper presents a review about graphene material and its potential use in all technological fields. Due to its high conductivity, transparency and amazing properties. It seems that it has an important place in the next generation of solar cells instead of silicon or thin film based solar cells, researchers found diverse applications for graphene in nanoelectronics, aviation, industry, transport, biomedecine and others. This paper present a review about the state of art about the graphene material in photovoltaic solar cells where very interesting efficiencies were recorded.

Our effort towards the attainment of high performance devices has yielded several devices with total-area conversion efficiencies above 16%, the highest measuring 16.8% under standard reporting conditions (ASTM E892-87, Global 1000 W/m2). The first attempts to translate this development to larger areas resulted in an efficiency of 12.5% for a 16.8-cm2 monolithically interconnected submodule test structure, and 15.3% for a 4.85-cm2 single cell. Achievement of a 17.2% device efficiency fabricated for operation under concentration (22-sun) is also reported. All high efficiency devices reported here are made from graded bandgap absorbers. Bandgap grading is achieved by compositional Ga/(In+Ga) profiling as a function of depth. The fabrication schemes to achieve the graded absorbers, the window materials and contacting are described

J Nondestruct Eval (2010) 29: 38–42 DOI 10.1007/s10921-010-0063-7 Acoustic Properties of Selected Tropical Wood Species Yahya Sedik · Sinin Hamdan · Ismail Jusoh · Mahbub Hasan Published online: 12 February 2010 © Springer Science+Business Media, LLC 2010 ...

The single crystal of MoSe2 grown by
chemical vapour transport  (CVT)  technique are used for the
fabrication of Photoelectro chemical (PEC) solar cells. The
effect of the concentration of the electrolyte on the conversion
efficiency of the fabricated PEC solar cell is studied

The inability of a single-gap solar cell to absorb energies less than the band-gap energy is one of the intrinsic loss mechanisms which limit the conversion efficiency in photovoltaic devices. New approaches to “ultra-high” efficiency solar cells include devices such as multiple quantum wells (QW) and superlattices (SL) systems in the intrinsic region of a p-i-n cell of wider band-gap energy (barrier or host) semiconductor. These configurations are intended to extend the absorption band beyond the single gap host cell semiconductor. A theoretical model has been developed to study the performance of the strain-balanced GaAsP/InGaAs/GaAs MQWSC, and GaAs/GaInNAs MQWSC or SLSC. Our re-sults show that conversion efficiencies can be reached which have never been obtained before for a single-junction solar cell.