Photoactive perovskite quantum dot films, deposited via an inkjet printer, have been characterized by x-ray diffraction and x-ray photoelectron spectroscopy. The crystal structure and bonding environment are consistent with CsPbBr perovskite quantum dots. The current-voltage (I-V) and capacitance-voltage (C-V) transport measurements indicate that the photo-carrier drift lifetime can exceed 1 ms for some printed perovskite films. This far exceeds the dark drift carrier lifetime, which is below 50 ns. The printed films show a photocarrier density 10 greater than the dark carrier density, making these printed films ideal candidates for application in photodetectors. The successful printing of photoactive-perovskite quantum dot films of CsPbBr, indicates that the rapid prototyping of various perovskite inks and multilayers is realizable.

Boron carbide films, alloyed with aniline moieties, were deposited by plasma enhanced chemical vapor deposition (PECVD) from aniline and orthocarborane precursors and were found to exhibit composition-dependent drift carrier lifetimes as derived from I( V) and C( V)) measurements. For a film with an aniline/carborane ratio of 5:1, the effective drift carrier lifetimes are ∼80 μs at low bias voltage but quickly drop to a few microseconds with increasing bias. A film with a 10:1 aniline/carborane ratio, however, exhibited lifetimes of ∼6 μs, or less, at 1 kHz, and much smaller values at 10 kHz. These lifetimes are orders of magnitude longer than those in polyaniline films and comparable to those in PECVD carborane films without aromatic content. X-ray photoelectron spectroscopy (XPS), FTIR, and ellipsometry, combined with density functional theory (DFT)-based cluster calculations, indicate that aniline and orthocarborane moieties are largely intact within the films. Bonding occurs primarily between aniline C sites and carborane B sites, and the aniline coordination number per carborane icosahedron is ∼2 as the aniline/carborane ratio is increased from 3:1 to 10:1. This aniline/carborane coordination ratio independent of aniline/orthocarborane stoichiometry is consistent with the dependence of charge transport properties on aniline film content at high bias voltage.

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