Structural and photoelectrical properties of an MDMO-PPV/n-Si hybrid heterojunction photodiode for broadband detection
Küçük Resim Yok
Tarih
2026
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Organic-inorganic hybrid photodiodes are attractive for low-cost, broadband photodetection, yet the role of the polymer/Si interface on power-and wavelength-dependent performance is still not fully clarified. In this study, we fabricate a simple Al/MDMO-PPV/n-Si/Al heterojunction photodiode using a solution-processed MDMO-PPV interlayer and systematically correlate its structural, optical and electrical characteristics. UV-Vis spectroscopy reveals a pronounced absorption band at 478nm, and Tauc analysis yields a direct optical band gap of 2.28 eV. XRD and SEM measurements indicate a predominantly amorphous, porous polymer film with short-range order, providing interconnected pathways for charge transport. Current-voltage measurements under light illumination from 20 to 100 mWcm(-2) show clear rectification with negligible dark current. Thermionic-emission and Cheung analyses give ideality factors of 3.0-3.5 and zero-bias barrier heights of 0.69-0.74 eV, while the photocurrent follows a power law I-ph proportional to P-1.42, evidencing trap-assisted photoconduction. The device operates over 300-1050 nm, where the responsivity (R) increases from 0.15 to about 0.42 AW(-1), the photosensitivity (K) rises to approximate to 4 - 13, and the specific detectivity (D) improves from similar to 1.1 x 10(10) to similar to 1.8 x 10(10) Jones. Time-resolved measurements at 0V bias yield rise and fall times of 0.70 s and 0.94 s, respectively. These results demonstrate that an MDMO-PPV interlayer can efficiently extend n-Si photodiodes into the visible-NIR region and provide bias-free broadband detection, offering a scalable and low-cost platform for next-generation optoelectronic and sensing applications.
Açıklama
Anahtar Kelimeler
Mdmo-Ppv, Hybrid Optoelectronic Devices, Heterojunction, Photodetector, Responsivity, Eqe, Broadband Detection, Diode Parameters
Kaynak
Physica B-Condensed Matter
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
725
