RESUMO
Graphene nanoribbon heterostructures and heterojunctions have attracted interest as next-generation molecular diodes with atomic precision. Their mass production via solution methods and prototypical device integration remains to be explored. Here, the bottom-up solution synthesis and characterization of liquid-phase-processable graphene nanoribbon heterostructures (GNRHs) are demonstrated. Joint photoresponsivity measurements and simulations provide evidence of the structurally defined heterostructure motif acting as a type-I heterojunction. Real-time, time-dependent density functional tight-binding simulations further reveal that the photocurrent polarity can be tuned at different excitation wavelengths. Our results introduce liquid-phase-processable, self-assembled heterojunctions for the development of nanoscale diode circuitry and adaptive hardware.
RESUMO
We investigated the influence of two passivating molecules containing a PâO group on the performance of quasi-2D Dion-Jacobson halide perovskite light-emitting diodes, namely, triphenylphosphine oxide (TPPO) and diphenyl-4-triphenylsilylphenyl phosphine oxide (TSPO1). We found that both passivating molecules lead to increased efficiency compared to control devices, while they had opposite effects on device lifetime, with a decrease observed for TPPO and an increase observed for TSPO1. The two passivating molecules resulted in differences in energy-level alignment, electron injection, film morphology and crystallinity, and ion migration during operation. While TPPO resulted in improved photoluminescence decay times, overall higher maximum external quantum efficiency (EQE) and device lifetime were obtained for TSPO1 compared to TPPO (14.4% vs 12.4% EQE, 341 min vs 42 min T50).