CHAR-ZnO-2026-013

Sol-gel ZnO thin film — structural/morphological characterization (XRD/SEM/Raman)

Identity

Sample ID	CHAR-ZnO-2026-013
Title	Sol-gel ZnO thin film — structural/morphological characterization (XRD/SEM/Raman)
Status	Completed
Operator	B. Çelik
Laboratory / Facility	Materials Characterization Center

Substrate / Material

Substrate Material	Si (100) + glass
Active Layer Material	ZnO (zinc oxide) thin film

Notes

Tags	characterization, XRD, SEM, AFM, Raman, ZnO, crystallite
Notes	c-axis oriented ZnO via sol-gel spin-coat + 500 °C annealing; multi-technique analysis.

Process Steps

ZnO film — sol-gel spin-coat (Thin Film Fabrication)

Technique	Sol-gel
Material / Target / Precursor	Zinc acetate dihydrate + 2-methoxyethanol + MEA
Equipment	Laurell spin-coater + 500 °C muffle furnace
Substrate Temperature (°C)	25
Duration (min)	0.5
Rate (nm/min or Å/s)	3000 rpm 30 s × 5 layers
Target Thickness (nm)	250
Measured Thickness (nm)	240
Post-treatment	Each layer pre-baked at 300 °C; final crystallization at 500 °C / 1 h in air

XRD — phase and crystallite size (XRD)

Instrument	Rigaku SmartLab
Radiation	Cu Kα
2θ Range (°)	20–70
Step Size (°)	0.02
Scan Rate	2°/min
Phase Identification (ICDD/PDF)	Wurtzite ZnO (ICDD 00-036-1451)
Peaks (2θ / hkl / intensity)	(002) 34.4° dominant → c-axis orientation; (100) 31.8°, (101) 36.3° weak.
Crystallite Size (nm, Scherrer)	28

From the Scherrer equation, crystallite ≈ 28 nm for (002); strong c-axis texture.

SEM + AFM — morphology and roughness (Microscopy (SEM/AFM))

Technique	SEM
Instrument	Zeiss Sigma 300 (SEM) + Bruker Dimension (AFM)
Magnification	50,000×
Voltage (kV)	5
Scan Size	2 × 2 µm (AFM)
RMS Roughness (nm)	4.2
Scale Bar	200 nm
Caption	Dense, crack-free granular surface; average grain ≈ 30–40 nm; AFM RMS ≈ 4.2 nm.

Raman — vibrational modes (Spectroscopy)

Technique	Raman
Instrument	Renishaw inVia (532 nm)
Range	100–800 cm⁻¹
Resolution	1 cm⁻¹
Peaks / Bands	E₂(high) 437 cm⁻¹ dominant; A₁(LO) 580 cm⁻¹ weak.
Assignment / Interpretation	Sharp E₂(high) → good crystal quality; weak A₁(LO) → low oxygen vacancy/free carrier.

Structural characterization summary (Result (Spec))

Parameter	Value	Uncertainty (±)	Unit	Specification	Pass
Dominant orientation	(002) c-axis		—	(002)	✓
Crystallite size (Scherrer)	28	3	nm	≥20	✓
RMS roughness (AFM)	4.2	0.4	nm	≤6	✓
Optical band gap (Tauc)	3.28	0.02	eV	3.2–3.3	✓

Grain size statistics (SEM, n=120) (Statistics / Data Summary)

N (sample count)	120
Mean	34 nm
Std. Deviation	8 nm
CV (%)	23.5%
Min	18 nm
Max	56 nm
Method / Software	ImageJ grain analysis (SEM 50k×, 120 grains)