Band gaps of doped and undoped films of molecular icosahedra

Defect contributions to conductivity in poly(3‐hexylthiophene)?

“…Combined photoemission and inverse photoemission were undertaken to study the molecular orbital placement of both occupied and unoccupied orbitals of the adsorbed molecules on Au(111) surfaces. All inverse photoemission (IPES) spectra were obtained with the electron gun at normal incidence and the detector positioned at 45° off the surface normal, as described elsewhere [8,9]. Both high resolution and angle-resolved photoemission studies were undertaken.…”

The coadsorption and interaction of molecular icosahedra with mercury

“…The evidence for metallic mercury, from the Hg 5d 5/2 core level widths does not suggest that mercury atoms may form a lattice which weakly interacts with orthocarborane lattice, or Hg may form a wetting surfactant layer and a layer between the Cu substrate and orthocarborane molecular fi lm which would easily explain a uniform shift in the molecular orbital photoemission binding energies. In this regard, Hg is very different from the more homo geneous mixtures formed with some metals and molecularly chemisorbed species [14][15][16][38][39][40][41][42][43][44][45][46][47][48][49].…”

“…Following the adsorption of closo-1,2-dicarbadodecaborane, C 2 B 10 ·H 12 (orthocarborane) on Cu(100)at 180 K, the highest occupied molecular orbital (HOMO) appears in the pho toemission spectra at an initial binding energy of 5.7 eV below the Fermi level, while the lowest unoccupied molecular orbital (LUMO) is observed at roughly 4.25 eV with respect to the Fermi level (E − E F ) [14,15,33]. This HOMO-LUMO gap is generally consistent with theory [14][15][16]33].…”

“…Hg and alkali metal mixtures with molecules have a long his tory in the study of non-metal to metal transitions [11,12]. This has been ex tended to the study of metal coadsorp tion with icosahedral molecular carbo ranes [13][14][15][16], in part motivated by the large highest occupied to lowest un occupied molecular orbital (HOMO-LUMO) band gap of the icosahedral carboranes and their nearly spherical shape [13]. Orthocarborane has quali ties which make it an interesting mate rial when used in studying the coadsorp tion behavior of different metals with the molecular fi lms.…”

“…For example, the HOMO-LUMO orbitals can be easily identifi ed, and the orthocarborane ad sorption is molecular. Alkali metal mix tures with molecular carboranes have been studied through the nonmetal to metal transition [13][14][15]. Hg and mo lecular carborane mixtures [16] have not lended themselves to studies of the nonmetal to metal transition as ho mogeneous mixtures of the carborane molecules and mercury do not readily form.…”