לוח שנה משולב

Organic Photovoltaics offer the promise of low cost high performance photovoltaics. One of the key areas for improvement is in developing selective contacts that improve efficiency and lifetime. We will report on the development of novel inorganic hole transport layers (HTL) and the related electron transport layers (ETL) for organic photovoltaics (OPV). All the studied materials belong to the general class of wide-bandgap p-type oxide semiconductors. Coupled to the “conventional TCO’s” the pairing of new materials by design for the HTL and ETL potentially can improve efficiency and stability tailored to a particular bulk heterojunction. How we can begin to to design such materials and then realize them experimentally is the topic of the talk. Potential candidates suitable for HTL applications include SnO, NiO, MO3, Cu2O (and related CuAlO2, CuCrO2, SrCu2O4 etc) and Co3O4 (and related ZnCo2O4, NiCo2O4, MgCo2O4 etc.). Materials have been optimized by high-throughput combinatorial approaches. The thin films were deposited by RF sputtering and pulsed laser deposition at ambient and elevated temperatures. Performance of the inorganic HTLs and that of the reference organic PEDOT:PSS HTL were compared by measuring the power conversion efficiencies and spectral responses of the P3HT/PCBM- and PCDTBT/PCBM-based OPV devices. Preliminary results indicate that Co3O4-based HTLs have performance comparable to that of our previously reported NiOs and PEDOT:PSS HTLs, leading to a power conversion efficiency of about 4 percent. The effect of composition and work function of the ternary materials on their performance in OPV devices is under investigation.

High-Tc cuprate superconductors display startling nanoscale inhomogeneity in essential properties such as pseudogap energy scale, Fermi surface, and even superconducting
critical temperature. The direct cause of this inhomogeneity has remained mysterious; theoretical explanations have ranged from chemical disorder to spontaneous electronic phase separation. We extend the energy range of scanning tunneling spectroscopy, allowing the first complete mapping of all three types of oxygen dopants in Bi(2+y)Sr(2-y)CaCu2O(8+x) with maximum superconducting Tc ~ 90K. We show that a subset of these dopants are indeed the hidden variable at the root of the nanoscale disorder. We explain how the spatial variations in competing electronic orders, such as the pseudogap and the charge density wave, are governed by the disorder in the dopant concentrations, which suggests a possible avenue
to raise Tc in this material.

Following high demand for the Volocity tutorial we are announcing a second tutorial on Sunday, March 18.
The tutorial will introduce the Volocity 3D-4D imaging software by Perkin-Elmer.
It will include lectures as well as hands-on practice sessions.
It will cover basic usage, visualization modes, segmentation, tracking, co-localization, measurements and other topics.

Date and Time: Monday, March 18, 2012, 09:00 - 16:00
Location: Levine building, comuter classroom
The tentative schedule is:
9-11: lecture
11-13: hands-on session
13-14: lunch break
14-16: hands-on session continue

The planned agenda is:
Lecture
9. introduction of the software
10. Introduction to multiple dimensions representation problem.
11. The software modules: Acquisition, Quantitation, Restoration, Visualization
12. The Weizmann current repository and the demo version
13. Downloading, Installing and Running
14. General window structure
15. The library content: PSF, Measurements, Folders , Images, Image sequence and volume construction, Display modes
16. The image window: The image, sequence and measurement tabs
Hands-on Topics
7. Importing data, conducting simple measurements and exporting results.
8. Volume and time-laps measurements
9. Populations (including colocalization)
10. Tracking
11. Displaying results (visualization options)
12. Deconvolution

Registration is mandatory as the number of participants is limited by the number of available computer stations.
For registration please email: ofra.golani@weizmann.ac.il