Downscaling the Sample Thickness to Sub-Micrometers by Employing Organic Photovoltaic Materials as a Charge-Generation Layer in the Time-of-Flight Measurement
نویسندگان
چکیده
Time-of-flight (TOF) measurements typically require a sample thickness of several micrometers for determining the carrier mobility, thus rendering the applicability inefficient and unreliable because the sample thicknesses are orders of magnitude higher than those in real optoelectronic devices. Here, we use subphthalocyanine (SubPc):C70 as a charge-generation layer (CGL) in the TOF measurement and a commonly hole-transporting layer, N,N'-diphenyl-N,N'-bis(1,1'-biphenyl)-4,4'-diamine (NPB), as a standard material under test. When the NPB thickness is reduced from 2 to 0.3 μm and with a thin 10-nm CGL, the hole transient signal still shows non-dispersive properties under various applied fields, and thus the hole mobility is determined accordingly. Only 1-μm NPB is required for determining the electron mobility by using the proposed CGL. Both the thicknesses are the thinnest value reported to data. In addition, the flexibility of fabrication process of small molecules can deposit the proposed CGL underneath and atop the material under test. Therefore, this technique is applicable to small-molecule and polymeric materials. We also propose a new approach to design the TOF sample using an optical simulation. These results strongly demonstrate that the proposed technique is valuable tool in determining the carrier mobility and may spur additional research in this field.
منابع مشابه
Field Dependent Charge Carrier Transport for Organic Semiconductors at the Time of Flight Configuration
In this paper, we used the time-of-flight (TOF) of a charge packet, that injected by a voltage pulse to calculate the drift velocity and mobility of holes in organic semiconducting polymers. The technique consists in applying a voltage to the anode and calculating the time delay in the appearance of the injected carriers at the other contact. The method is a simple way to determine the charge t...
متن کاملRestricted charge recombination process in PbS quantum dot sensitized solar cells by different coating cycles of ZnS films
The relatively low power conversion efficiency (PCE) of quantum dot sensitized solar cells (QDSSCs) is attributed to charge recombination at the interfaces. Charge recombination process could be suppressed by coating the QD layer with a wide band gap semiconductor such as ZnS, which acts as a blocking layer between the QDs and hole transport material (HTM). In present study, to improve PCE of P...
متن کاملStudy on Wicking Measurement in Thin Layer Textiles by Processing Digital Images
The purpose of this work is to assess and develop experimental techniques that allowwicking measurement over a wide range of textiles. Various kinds of fabrics, nonwoven layers and anelectro spinning nylon layer were used as the test materials. A syringe is used to drop a 0.02 g spot ofdistilled water on the sample and a digital camera to take pictures simultaneously. When the wickingprocess st...
متن کاملSynthesis and Investigation of Photovoltaic Properties of New Organic Dye in Solar Cells Device
In this paper, we designed and synthesized free-metal dyes based on indoline. The proposed dyes were synthesized from phenothiazine as the starting material by standard reactions. The chemical structure of the synthesized dye was confirmed using FT-IR, 1HNMR and DSC techniques. Spectrophotometric measurements of the organic dyes in acetonitrile and on a TiO2 substrate ...
متن کاملAn Electrochemical Investigation of Nano Cerium Oxide/Graphene as an Electrode Material for Supercapacitors
In this paper, the effect of cationic and anionic ion sizes on the charge storage capability of graphene nanosheets is investigated. The electrochemical properties of the produced electrode are studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques in 3M NaCl, NaOH, and KOH electrolytes. Scanning electron microscopy (SEM) is used to characterize the mi...
متن کامل