Overview
IEC 62899-503-1:2020 defines a standardized test method for displacement current measurement (DCM) applied to printed thin-film transistors (printed TFTs) and organic thin-film transistors (OTFTs). The standard describes the measurement setup, environmental conditioning, measurement procedure and reporting requirements used to characterize carrier behavior, charge trapping and channel capacitance in printed electronics. It is part of the IEC 62899 series on printed electronics and was prepared by IEC TC 119.
Key topics and requirements
- Scope: Specifies DCM for printed TFTs / OTFTs as a direct method to detect charge motion between source/channel/drain and gate.
- Measurement principle: Apply a triangular gate voltage waveform and record source and drain currents (I_S and I_D) versus gate-to-source voltage (U_GS). Compute displacement current (I_dis), trapped charge (Q_trap and ΔQ_trap) and injected/ejected carrier charges.
- Apparatus: Typical instruments include a function generator, amplifier, oscilloscope and low-noise power/battery, plus an electronic measurement kit to minimize external parasitic capacitance introduced by probes and cables.
- Procedure highlights:
- Mount specimen per figure and wiring schema in the standard.
- Apply triangle wave with constant amplitude and frequency to the gate.
- Measure I vs U for source and drain, calculate displacement current and integrate to obtain charges and channel capacitance.
- Use Annex A for charge trapping and channel capacitance measurement details.
- Environmental conditions: Conditioning and testing atmospheres per ISO 291 - generally (23 ± 2) °C and (50 ± 10) % RH; tighter class-1 conditions for plastic substrates (23 ± 1 °C, 50 ± 5 % RH).
- Reporting: Include experimental conditions, data formats, measured symbols (e.g., Q_trap, C_channel), and test frequency dependence.
Applications and users
IEC 62899-503-1 is intended for:
- R&D teams characterizing carrier injection, trapping and mobility in printed/organic semiconductors.
- Quality assurance and process control for printed TFT manufacturing.
- Materials and ink suppliers validating semiconductor or dielectric performance.
- Test labs and conformity assessors evaluating device reliability and electrical properties.
- Designers of flexible electronics, sensors, displays and other printed-electronics products who require quantitative channel-capacitance and trapping metrics.
Practical benefits include standardized, repeatable DCM measurements that help troubleshoot contact injection issues, evaluate dielectric/semiconductor interfaces, and compare device batches.
Related standards
- IEC 62899 series (Printed electronics) - other parts cover component and quality assessment topics (see IEC webstore for the full list).
- ISO 291 - referenced normative standard for conditioning and test atmospheres.
Keywords: IEC 62899-503-1, displacement current measurement, DCM, printed TFT, OTFT, charge trapping, channel capacitance, printed thin-film transistor, printed electronics.
Open preview (PDF)Printed electronics - Part 503-1: Quality assessment - Test method of displacement current measurement for printed thin-film transistor
