Preparation of PMMA-based semiconductor / Rabaitul Waqiah Zakariya

In this study the Poly (methyl methacrylate) block with 10 mm thickness
was irradiated using Electron Beam Accelerator at 50 kGy radiation dose.
The energy band gap obtained from this irradiated sample was 3.50 eV
which falls in the range of most common semiconductors. From the Hot
Probe measurement, it was found that this irradiated PMMA was an n-type
semiconductor. Therefore, it can be concluded that the charge carriers in
this irradiated PMMA system were electrons. These electrons were
released from the breaking of CH2 and CH3 groups of PMMA structure
that had been confirmed from the Fourier Transform Infrared analysis
(FTIR). The decrease in the glass transition temperature, Tg and the
decomposition temperatures, Td of the irradiated PMMA system obtained
from the differential scanning calorimetry (DSC) and thermogravimetric
analysis (TGA) thermogram supported the occurrence of bond breaking in
the structure. This can also be confirmed from the roughness structure
obtained in the optical micrograph of the irradiated PMMA.