Achieving current rectification ratios ≥ 10⁵ across thin films of coordination polymer

Abstract

A record value of the current rectification ratio (RR ≥ 105) across molecularly doped thin films of a Cu(ii)-coordination polymer is achieved.

Emergent Interface in Heterostructured Thin Films of Cu(II) and Cu(I) Coordination Polymers

“…Thus, top and bottom layers of our AB-type heterostructured thin film are behaving as n-type and p-type semiconductors, respectively, complementing I−V characteristics of commercial p−n junction Si diode (Figure S19). 59 To further support our claim on the emergence of p−n junction interface in AB-and BA-type heterostructured thin films, we have recorded capacitance−voltage (C−V) characteristics and plotted 1/C 2 versus V, the so-called Mott−Schottky (MS) plot. Our MS exhibited both positive and negative slopes with inverted V-like shape (likewise observed for inorganic oxide/sulfide semiconductor heterostructures 60,61 ) where the negative slope represents the p-type semiconductor Cu-BTC with a hole as the majority charge carrier and the positive slope represents the n-type semiconductor Cu-TCNQ with electrons as the majority charge carrier (Figure S20).…”

Charge-transfer interface of insulating metal-organic frameworks with metallic conduction

“…Such an impregnation of TCNQ resulted in successful transformation of an insulating MOF (Cu-BTC) to a semiconductor material (TCNQ@Cu-BTC) 17 , 18 , 21 , 22 . Motivated by these remarkable observations, we have deliberately impregnated Cu-BPyDC thin film with TCNQ following our standardized procedure 35 (similar to the one reported by Allendorf et al 17 ) and performed a comparative assessment of TCNQ@Cu-BPyDC thin film with hetero-structured Cu-TCNQ/Cu-BPyDC thin film. It is worth to mention here that in a recent study 24 , we were able to successfully fabricate hetero-structured Cu-TCNQ/Cu-BTC thin film by carefully avoiding the impregnation of TCNQ in Cu-BTC framework, and the same approach has been adopted in the present work i.e., upon reducing the reaction time of the initial few LbL growth cycles of Cu-TCNQ on top of Cu-BPyDC thin film.…”

Programmed Molecular Assembly of Abrupt Crystalline Organic/Organic Heterointerfaces Yielding Metal‐Organic Framework Diodes with Large On‐Off Ratios

“…[ 23 ] By a diffuse doping gradient of TCNQ in the film, a diode‐like current rectification was demonstrated. [ 24 ] With respect to electronic applications, field‐effect transistors, [ 25 ] solar cells [ 26 ] and light‐emitting diodes [ 27,28 ] with MOFs as active layer were realized. The efficiency of the presented devices is far from ideal, also due to the poorly‐defined interface between the layers.…”