Keith E. Fogel

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The performance of optimized graphene devices is ultimately determined by the quality of the graphene itself. Graphene grown on copper foils is often wrinkled, and the orientation of the graphene cannot be controlled. Graphene grown on SiC(0001) via the decomposition of the surface has a single orientation, but its thickness cannot be easily limited to one(More)
Forty gay men who had recently learned that they were infected with human immunodeficiency virus (HIV) were interviewed to determine the frequency with which they voluntarily informed physicians, dentists, friends, family members, and current and past sexual partners of their positive test results. Ninety percent of the subjects informed a personal(More)
  • D Shahrjerdi, S W Bedell, C Ebert, C Bayram, B Hekmatshoar, K Fogel +5 others
  • 2012
In this letter, we demonstrate the effectiveness of the controlled spalling technology for producing high-efficiency (28.7%) thin-film InGaP/(In)GaAs/Ge tandem solar cells. The controlled spalling technique was employed to separate the as-grown solar cell structure from the host Ge wafer followed by its transfer to an arbitrary Si support substrate. The(More)
Flexible solar cells are envisioned to open up a myriad of possibilities for enabling new applications in consumer electronics and space satellites. [ 1–3 ] Organic and amorphous semiconductors hold a great promise for realizing bendable and lightweight solar cells, largely due to their fairly strong light absorption properties, process temperature(More)
A fracture-based layer transfer technique referred to as controlled spalling was used to separate a conventional InGaN/GaN multiple quantum well light-emitting diode (LED) structure from a 50 mm sapphire wafer enabling the formation of vertical spalled LEDs (SLEDs). A 25-m-thick tensile Ni layer was electrodeposited on the surface of the wafer, followed by(More)
This is the first report showing VIP fibers in the optic chiasm and the optic nerves of intact rats. These fibers form a fan-shaped dorso-medial bundle in the optic nerves. After colchicine injection into the vitreous body VIP fibers could be followed farther in the optic nerve toward the eye when compared to intact rats. After removal of eyes (enucleation)(More)
Thin, lightweight and flexible electronics are being regarded as an important evolutionary step in the development of novel technological products. Interestingly, this trend has emerged in a wide range of industries; from microelectronics to photovoltaics and even solid state lighting. Historically, most attempts to enable flexibility have focused on the(More)
  • Claiborne O Mcpheeters, Edward T Yu, H W J Shockley, Queisser, K M W J Mazzer, I M Barnham +138 others
  • 2012
Simulations of thin film (~2.5 µm thick) InGaAs/GaAs quantum well solar cells with various back side reflective and planar, symmetric scattering structures used for light trapping have been performed using rigorous coupled-wave analysis. Two-dimensional periodic metal/dielectric scattering structures were numerically optimized for Airmass 0 photocurrent(More)
Pituitary adenylate cyclase activating polypeptide (PACAP) is a member of the secretin family. It is widely distributed in the central and peripheral nervous systems. The highest concentration of PACAP was found in the hypothalamus. In the present work it has been studied whether PACAP is involved in the mediation of photic stimuli to the anterior pituitary(More)