Carbon nanotube intramolecular p-i-n junction diodes with symmetric and asymmetric contacts

Abstract

A p-i-n junction diode based on the selectively doped single-walled carbon nanotube (SWCNT) had been investigated, in which two opposite ends of individual SWCNT channel were doped into the p- and n-type SWCNT respectively while the middle segment of SWCNT was kept as the intrinsic. The symmetric and asymmetric contacts were used to fabricate the p-i-n junction diodes respectively and studied the effect of the contact on the device characteristics. It was shown that a low reverse saturation current of ~20 pA could be achieved by these both diodes. We found that the use of the asymmetric contact can effectively improve the performance of the p-i-n diode, with the rectification ratio enhanced from ~102 for the device with the Au/Au symmetric contact to >103 for the one with the Pd/Al asymmetric contact. The improvement of the device performance by the asymmetric-contact structure was attributed to the decrease of the effective Schottky-barrier height at the contacts under forward bias, increasing the forward current of the diode. The p-i-n diode with asymmetric contact also had a higher rectification ratio than its counterpart before doping the SWCNT channel, which is because that the p-i-n junction in the device decreased the reverse saturated current.

WSe2 Photovoltaic Device Based on Intramolecular p–n Junction

“…Selectively doping MoS 2 by AuCl 3 , an in‐plane MoS 2 p–n junction is realized, achieving the open‐circuit voltage ( V oc ) of 0.2 V and short‐circuit current ( I sc ) of 31.2 nA with 40 V back‐gate voltage at the wavelength of 600 nm . Triethyloxonium hexachloroantimonate (OA) and polyethyleneimine (PEI) have also been proved to be effective holes and electrons chemical doping agents for carbon nanotubes, respectively . An intramolecular p–i–n junction has been realized on a single carbon nanotube through region‐selectable chemical doping process .…”

In-materio computing in random networks of carbon nanotubes complexed with chemically dynamic molecules: a review

“…Using this method, high-performance diodes with a high rectification ratio, large forward current, and low reverse saturation current have been realized [25], and the I-V characteristics show clear nonlinear rectifying properties. An asymmetric contact was found to effectively improve p-i-n diode performance [26]. A three-dimensional electrolyte-accessible electrode structure was developed to achieve a highperformance rate in an organic electrolyte.…”

Fully Printed and Flexible Schottky Diodes Based on Carbon Nanomaterials Operating Up to 5 MHz

“…Solution-processable materials are probably the most promising candidates, as they can be cost-effectively deposited over a large area using high-throughput techniques compatible with direct printing on different flexible substrates [8]- [10]. Numerous diodes based on solution processed lowdimensional [11]- [14], organic [15]- [21] and metal-oxide [22]- [25] semiconductors have been reported on both rigid and flexible substrates. Among the various available solutionprocessable materials, carbon-based nanomaterials, such as semiconducting carbon nanotubes (CNT) and graphene, have demonstrated compatibility with printing techniques and remarkable properties in printed devices [26]- [28].…”