We report NREL-certified efficiencies and initial lifetime data for organic photovoltaic (OPV) cells based on Plexcore
PV photoactive layer and Plexcore HTL-OPV hole transport layer technology. Plexcore PV-F3, a photoactive layer
OPV ink, was certified in a single-layer OPV cell at the National Renewable Energy Laboratory (NREL) at 5.4%, which
represents the highest official mark for a single-layer organic solar cell. We have fabricated and measured P3HT:PCBM
solar cells with a peak efficiency of 4.4% and typical efficiencies of 3 - 4% (internal, NREL-calibrated measurement)
with P3HT manufactured at Plextronics by the Grignard Metathesis (GRIM) method. Outdoor and accelerated lifetime
testing of these devices is reported. Both Plexcore PV-F3 and P3HT:PCBM-based OPV cells exhibit >750 hours of
outdoor roof-top, non-accelerated lifetime with less than 8% loss in initial efficiency for both active layer systems when
exposed continuously to the climate of Western Pennsylvania. These devices are continuously being tested to date.
Accelerated testing using a high-intensity (1000W) metal-halide lamp affords shorter lifetimes; however, the true
acceleration factor is still to be determined.
The rapid growth of OLEDs will occur when device performance, particularly lifetime, and production costs are optimized. Plextronics Inc. is using a versatile technology platform to develop HIL technology that will address critical degradation factors of solution processed OLEDs. In particular, significant effort has been applied to understanding the impact of inputs including the inherently conductive polymer, dopant system, solvent system, and additional functional additives, on resulting HIL film properties, which are presented here.
We present initial measurements of the dispersive index of refraction for sodium matter waves passing through argon. In addition, we describe a novel scheme for performing tomography on the longitudinal quantum state of particles in an atomic beam.
Since the first interferometers for atoms and molecules were demonstrated in 1991, they have already been applied to measure atomic and molecular properties, to investigate fundamental aspects of quantum mechanics, and to measure inertial motion. This tutorial is designed to introduce those with a vague understanding of optical interferometers to atom interferometry. We outline the basic theory needed to calculate the observed phase shift, indicate how this phase shift is experimentally determined, and then describe how the phase shift is found in two particular cases: phase shifts caused by application of a uniform electric field to atoms on one side of the interferometer, and phase shift arising from the presence of a gaseous medium through which the atom wave on one side of the interferometer must propagate. We illustrate this presentation with a description of our three grating interferometer, including data taken with it.