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While previously published experimental results have shown that the step-free (0 0 0 1) 4H-SiC mesa growth surface uniquely enables radical improvement of 3C-SiC and 2H-AlN/GaN heteroepitaxial film quality (>100-fold reduction in extended defect densities), important aspects of the step-free mesa heterofilm growth processes and resulting electronic device benefits remain to be more fully elucidated. This paper reviews and updates recent ongoing studies of 3C-SiC and 2H-AlN/GaN heteroepilayers grown on top of 4H-SiC mesas. For both 3C-SiC and AlN/GaN films nucleated on 4H-SiC mesas rendered completely free of atomic-scale surface steps, TEM studies reveal that relaxation of heterofilm strain arising from in-plane film/substrate lattice constant mismatch occurs in a remarkably benign manner that avoids formation of threading dislocations in the heteroepilayer. In particular, relaxation appears to occur via nucleation and inward lateral glide of near-interfacial dislocation half-loops from the mesa sidewalls. Preliminary studies of homojunction diodes implemented in 3C-SiC and AlN/GaN heterolayers demonstrate improved electrical performance compared with much more defective heterofilms grown on neighbouring stepped 4H-SiC mesas. Recombination-enhanced dislocation motion known to degrade forward-biased 4H-SiC bipolar diodes has been completely absent from our initial studies of 3C-SiC diodes, including diodes implemented on defective 3C-SiC heterolayers grown on stepped 4H-SiC mesas. [ABSTRACT FROM AUTHOR]

Perovskite quantum dots (PQDs) are a competitive candidate for next‐generation display technologies as a result of their superior photoluminescence, narrow emission, high quantum yield, and color tunability. However, due to poor thermal resistance and instability under high energy radiation, most PQD‐based white light‐emitting diodes (LEDs) show only modest luminous efficiency of ≈50 lm W−1 and a short lifetime of <100 h. In this study, by incorporating cellulose nanocrystals, a new type of QD film is fabricated: CH3NH3PbBr3 PQD paper that features 91% optical absorption, intense green light emission (518 nm), and excellent stability attributed to the complexation effect between the nanocellulose and PQDs. The PQD paper is combined with red K2SiF6:Mn4+ phosphor and blue GaN LED chips to fabricate a high‐performance white LED demonstrating ultrahigh luminous efficiency (124 lm W−1), wide color gamut (123% of National Television System Committee), and long operation lifetime (240 h), which paves the way for advanced lighting technology. [ABSTRACT FROM AUTHOR]

Abstract: We have developed flexible top emission organic light-emitting devices by using sputtered Ni films on the parylene coated copy paper substrates. The Ni film grew through the coalescence of the Ni islands nucleated on the cellulose fiber patterns. The parylene, acting as a buffer layer for preventing water absorption, affected the morphological and electrical characteristics of the deposited Ni films. The flexible top emission diode device composed of Ni anode and Ca/Ag semitransparent cathode exhibited a luminance of ∼1 cd/m2 at a driving voltage of 14.5 V. [ABSTRACT FROM AUTHOR]