S. Pillai would like to acknowledge the UNSW Faculty
of Engineering Research Scholarship. K.R. Catchpole
acknowledges the support of an Australian Research Council fellowship.

/pdf/surface-plasmon-enhanced-silicon-solar-cells-3duyubxz7i.pdf

Surface plasmon enhanced silicon solar cells

The scattering from metal nanoparticles near their localized plasmon resonance is a promising way of increasing the light absorption in thin-film solar cells. Enhancements in photocurrent have been observed for a wide range of semiconductors and solar cell configurations. We review experimental and theoretical progress that has been made in recent years, describe the basic mechanisms at work, and provide an outlook on future prospects in this area.

https://openresearch-repository.anu.edu.au/bitstream/10440/1045/1/Catchpole_Plasmonic2008.pdf

Plasmonic solar cells

Organic solar cells are promising for technological applications, as they are lightweight and mechanically robust. This study presents flexible organic solar cells that are less than 2 μm thick, have very low specific weight and maintain their photovoltaic performance under repeated mechanical deformation.

/pdf/ultrathin-and-lightweight-organic-solar-cells-with-high-4rp3u0tfpt.pdf

Ultrathin and lightweight organic solar cells with high flexibility

Power consumption is forecast by the International Technology Roadmap of Semiconductors (ITRS) to pose long-term technical challenges for the semiconductor industry. The purpose of this paper is threefold: (1) to provide an overview of strategies for powering MEMS via non-regenerative and regenerative power supplies; (2) to review the fundamentals of piezoelectric energy harvesting, along with recent advancements, and (3) to discuss future trends and applications for piezoelectric energy harvesting technology. The paper concludes with a discussion of research needs that are critical for the enhancement of piezoelectric energy harvesting devices.

/pdf/powering-mems-portable-devices-a-review-of-non-regenerative-30r5zxggdp.pdf

Powering MEMS portable devices—a review of non-regenerative and regenerative power supply systems with special emphasis on piezoelectric energy harvesting systems

Multicrystalline silicon wafers, widely used in commercial photovoltaic cell production, traditionally give much poorer cell performance than monocrystalline wafers (the previously highest performance laboratory devices have solar energy conversion efficiencies of 186% and 240%, respectively) A substantially improved efficiency for a multicrystalline silicon solar cell of 198% is reported together with an incremental improvement in monocrystalline cell efficiency to 244% The improved multicrystalline cell performance results from enshrouding cell surfaces in thermally grown oxide to reduce their detrimental electronic activity and from isotropic etching to form an hexagonally symmetric “honeycomb” surface texture This texture reduces reflection loss as well as substantially increasing the cell’s effective optical thickness by causing light to be trapped within the cell by total internal reflection

19.8% efficient “honeycomb” textured multicrystalline and 24.4% monocrystalline silicon solar cells

Significant performance increase for silicon solar cells is reported. This has been achieved by a combination of several mechanisms. One is the reduction of recombination at cell surfaces using atomic hydrogen passivation of silicon/silicon dioxide interfaces. Joule resistive losses in the cell have been reduced by a process which allows different thickness for fine and coarse features in the top cell metallization. Finally, reflection losses have been reduced by the use of a double layer antireflection coating. For successful incorporation, this required the development of techniques for growing the surface passivating oxide very thin, without reducing its passivation qualities. The cells display a monochromatic light energy conversion efficiency of 46.3% for 1.04 μm wavelength light, also the highest ever for a silicon devices.

Twenty‐four percent efficient silicon solar cells with double layer antireflection coatings and reduced resistance loss

The Centre of Excellence for Advanced Silicon Photovoltaics
and Photonics is supported under the Australian
Research Council’s Centres of Excellence Scheme.

/pdf/enhanced-emission-from-si-based-light-emitting-diodes-using-1wjnf3nv8v.pdf

Enhanced emission from Si-based light-emitting diodes using surface plasmons

http://www.unife.it/scienze/astro-fisica/insegnamenti/ottica-applicata/materiale-didattico/misure-ottiche_riflettometri/ROSE_optcomm_1999_b.pdf/at_download/file

Angle-dependent reflectance measurements on photovoltaic materials and solar cells

The dark I-V characteristics of crystalline silicon solar cells usually deviate from that expected by classical diode theory by an unusually high ideality factor and magnitude at biases smaller than about 0.5 V. It had been shown that the recombination current is flowing preferentially in certain local extended defect positions like the edge or local shunts. There, the local density of recombination centers in the pn-junction is higher than in the bulk by orders of magnitude. In this work, we go beyond the SRH theory to explain the recombination effects occurring in such heavily damaged pn-junction regions. Firstly, we apply the coupled defect recombination via two shallow (or one shallow and one deep) level, which explains the observed high ideality factors due to trap-assisted tunneling. Secondly, we apply the coupling of two defects to recombination via deep donor-acceptor pairs, which cause the high ideality factors due to saturation of the recombination rate between the two defects. Thirdly, the local extension of the recombination region across the edge of the cell (due to electrostatic charging) is an other explanation of very high recombination currents.

/pdf/interpretation-of-the-commonly-observed-i-v-characteristics-4d6mvt6aut.pdf

J. Zhao

Papers

Twenty‐four percent efficient silicon solar cells with double layer antireflection coatings and reduced resistance loss

Enhanced emission from Si-based light-emitting diodes using surface plasmons

Angle-dependent reflectance measurements on photovoltaic materials and solar cells

Interpretation of the Commonly Observed I-V Characteristics of C-SI Cells Having Ideality Factor Larger Than Two

Minority carrier lifetime in plasma-textured silicon wafers for solar cells