Organic Thin-film Technology Research Articles

A study of the potential benefits of semi-transparent photovoltaics in commercial buildings

This study investigates the potential benefits of semi-transparent photovoltaic windows on the energy, daylighting and thermal performance of commercial buildings. A general simulation methodology is proposed and utilized, integrating thermal, electrical and daylighting analysis. The impact of various building design parameters on the selection of ideal optical properties of semi-transparent photovoltaics is examined. The potential performance of Poly-Si, a-Si/μc-Si and organic cell technologies is also studied. The selection of the module optical properties is shown to be sensitive on the daylight and lighting controls applied and photovoltaic cell technology utilized. The selection of a semi-transparent photovoltaic module with 10% visible effective transmittance resulted in the lowest annual end-use electricity consumption (as low as 5kWh/m2/yr). Finally, simulation results suggest that high cell operating temperatures of up to 64°C could occur that might cause accelerated degradation when organic thin film technologies are used.

Lighting Up Ultraviolet Fluorescence From Chicken Albumen Through Plasmon Resonance Energy Transfer of Gold Nanoparticles

Au nanoparticles (AuNPs), which easily aggregate in organic thin film, are observed to well-disperse in chicken albumen thin films. The incorporated AuNPs is distributed uniformly inside the thin film and is as dense as 650 (particles/μm3). In addition, enhanced ultraviolet (UV) fluorescence centered at 350 nm is observed from the AuNPs-containing chicken albumen thin film. The enhancement is proposed to be originated from the plasmon resonance energy transfer (PRET) from the d-band absorption of AuNPs to the chicken albumen protein. The enhanced fluorescence is further verified by the shorter fluorescence lifetime from the time-resolved fluorescence spectra. These results indicate that d-band transition of AuNPs can be used to interface with other UV-emitting biomolecules. Results in this study demonstrate that AuNPs exhibit future potentials in applications for both the organic thin-film technology and nano-biotechnology.

Organic dual DC-DC upconverter on foil for improved circuit reliability

A report is presented on the design and measurement of one of the first dual DC-DC upconverters implemented in an organic thin-film technology on foil providing output voltages beyond the upper and lower power supply voltages. The converter generates bias voltages around +50 and −40 V from a 20 V power supply. The upconverted voltage range is sufficient to bias backgates of transistors in dual-gate thin-film transistor technologies, which improves the reliability of analogue as well as digital thin-film circuits.

Organic complementary oscillators with stage-delays below 1 μs

Recently, complex circuits of organic thin-film transistors have been shown. The use of complementary logic can significantly ease the design of large integrated circuits. However, the performance of complementary logic in organic thin-film technology has not been able to equivale that of unipolar logic, due to the difficulty to densely integrate and simultaneously optimize p-type and n-type transistors on a single substrate. Here, we develop an optimized complementary process for C60 n-type and pentacene p-type transistors, both having bottom-gate bottom-contact geometry. Using this complementary technology, we show ring-oscillators with a stage-delay below 1 μs at a supply-voltage of 20 V.