1：Experimental Design and Method Selection:

The study involved the synthesis of 4-HDPA using a multi-step chemical route, followed by characterization of its thermal, optical, and electrochemical properties. OFET devices were fabricated with top-contact geometry for both thin films and single crystals to measure charge carrier mobility.

2：Sample Selection and Data Sources:

The compound 4-HDPA was synthesized from commercial reagents. Thin films were deposited on OTS-modified Si/SiO2 substrates, and single crystals were grown using physical vapor transport (PVT) method.

3：List of Experimental Equipment and Materials:

Equipment includes Bruker 400 NMR spectrometer, UV-3600 Plus spectrophotometer, CHI660C electrochemistry station, PERKIN ELMER TGA7, Nikon ECLIPSE Ci-POL microscopes, Bruker Dimension Icon AFM, SU8010 SEM, micromanipulator 6150 probe station, Keithley 4200-SCS. Materials include CDCl3, TMS, Bu4NPF6, OTS, gold for electrodes, and various chemicals for synthesis.

4：Experimental Procedures and Operational Workflow:

Synthesis involved reactions under inert atmosphere, purification by column chromatography. Substrates were cleaned and treated with OTS. Thin films were vacuum-deposited at controlled rates and temperatures. Single crystals were grown via PVT. Devices were fabricated by depositing gold electrodes and characterized electrically in air.

5：Data Analysis Methods:

Mobility was calculated from transfer and output characteristics using standard FET equations. Statistical analysis included mobility distribution from multiple devices.