Exploring the Temperature-Dependent Microelectrical Characteristics of Organic-Silicon Heterojunctions in the Absence of Luminance

Abstract

An organic−silicon (O/S) interface represents a fundamental heterojunction in semiconductor technology with significant implications for the advancement of electronic and optoelectronic devices. In this study, an organic−silicon heterojunction (PDI/p-c-Si) was synthesized by depositing a layer of perylene derivatives onto p-c-Si. The microelectrical properties of this junction were investigated in the absence of light, spanning temperatures from 300 K to 373 K, utilizing current− voltage (I−V) analysis, as well as Cheung's and Norde's approach. The I− V measurements of Ag (∼100 nm)/O-PDI or OD-PDI (∼120 nm)/p-c-Si/Al (∼100 nm) (organic−silicon devices) conducted at temperatures ranging from ∼300 K to ∼373 K exhibit exponential behavior in the lowvoltage region, resembling that of conventional metal−semiconductor (MS) junctions. This observation is the basis for the frequent use of the thermionic emission model in understanding the electrical characteristics of these heterojunction devices. We conducted a comparison of the I−V characteristics of devices fabricated using O-PDI and OD-PDI. Device A, featuring the structure Ag (∼100 nm)/O-PDI/p-c-Si/Al (∼100 nm), exhibited series resistance ranging from ∼1403 Ω to ∼317 Ω, whereas Device B, with the structure Ag (∼100 nm)/OD-PDI/p-c-Si/Al (∼100 nm), showed series resistance ranging from ∼2599 Ω to ∼472 Ω. The ideality factor ranged from ∼3.17 to ∼2.82 for Device A and from ∼4.61 to ∼3.77 for Device B over temperatures ranging from 300 K to 373 K. These results indicate superior device performance of O-PDI, which can be attributed to structural and morphological disparities between O-PDI and OD-PDI molecules.