Chemical Modification of Semiconductor Surfaces for Molecular Electronics

Abstract

Inserting molecular monolayers within metal/semiconductor interfaces provides one of the most powerful expressions of how minute chemical modifications can affect electronic devices. This topic also has direct importance for technology as it can help improve the efficiency of a variety of electronic devices such as solar cells, LEDs, sensors, and possible future bioelectronic ones. The review covers the main aspects of using chemistry to control the various aspects of interface electrostatics, such as passivation of interface states and alignment of energy levels by intrinsic molecular polarization, as well as charge rearrangement with the adjacent metal and semiconducting contacts. One of the greatest merits of molecular monolayers is their capability to form excellent thin dielectrics, yielding rich and unique current-voltage characteristics for transport across metal/molecular monolayer/semiconductor interfaces. We explain the interplay between the monolayer as tunneling barrier on the one hand, and the electrostatic barrier within the semiconductor, due to its space-charge region, on the other hand, as well as how different monolayer chemistries control each of these barriers. Practical tools to experimentally identify these two barriers and distinguish between them are given, followed by a short look to the future. This review is accompanied by another one, concerning the formation of large-area molecular junctions and charge transport that is dominated solely by molecules.

Multidentate Anchors for Surface Functionalization

“…The bottom-up surfacef unctionalization [1][2][3][4][5][6] has attracted considerable attention in the development of functional thin films and materials for aw ide range of interdisciplinary applications including molecular electronics, [7][8][9][10] electrochromism, [11] information storage, [12] sensors, [13] logic circuits, [14] andm olecular switches. [15][16][17][18][19] In this context, the chemistry of surface modification by self-assembled or -adsorbed monolayers (SAMs) and layer-by-layer (LBL) growth of multilayersi sh ighly promising to construct two-dimensional( 2D) and even three-dimensional (3D) chemical systemso ns urfaces.…”

Strategies for Improving the Performance and Application of MOFs Photocatalysts

“…At present, the photocatalytic materials are mainly inorganic semiconductors, such as TiO 2 , ZnO, and CdS . Their application in real life is greatly limited, due to their low light conversion efficiency and the difficulty in structural modification . It is necessary to develop new types of photocatalyst.…”

“…[59][60][61][62] Their application in real life is greatly limited, due to their low light conversion efficiency [63][64][65] and the difficulty in structural modification. [66][67][68] It is necessary to develop new types of photocatalyst.…”

Interfacial N→Sb Nonbonded Interaction Enhances the Photoelectronic Performance of PVP‐Capped Sb2S3 Amorphous Colloids

“…From the aspect of underlying mechanisms, it is found that the interactions between surface metal cations of semiconductor colloids and coordination atoms or ions (S, P, N, halide ions, etc.) of ligands affect significantly the interfacial electronic processes, including the defect passivation, band structures and Fermi levels, carrier concentration and conduction type as well as electron/hole mobility . For instance, the surface replacement of long‐chain organic surfactants with small inorganic ligands enables to greatly enhance the carrier mobility and (photo)electronic performance of semiconductor colloids (especially lead chalcogenides) ,.…”

“…of ligands affect significantly the interfacial electronic processes, including the defect passivation, band structures and Fermi levels, carrier concentration and conduction type as well as electron/hole mobility. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] For instance, the surface replacement of longchain organic surfactants with small inorganic ligands enables to greatly enhance the carrier mobility and (photo)electronic performance of semiconductor colloids (especially lead chalcogenides). [4][5][6][7][9][10][11] The band edge energies and the p-or n-type conduction of PbS QDs can be adjustable by altering the surface ligands of different intrinsic dipole moment.…”