Jessiena, Crescentiana Cathlea (2025) Pengembangan Divais Fotodetektor UV Berbasis Seng Oksida Sebagai Wearable UV Index Monitor. Other thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Sinar ultraviolet (UV) memiliki dampak signifikan terhadap kesehatan kulit manusia, dengan paparan berlebihan dapat menyebabkan penuaan dini hingga kanker kulit. Oleh karena itu, penting untuk mengembangkan sistem pemantauan paparan radiasi UV yang dapat digunakan. Penelitian ini bertujuan untuk mengembangkan fotodetektor UV berbasis seng oksida (ZnO), yang dikenal memiliki sensitivitas tinggi terhadap radiasi UV, untuk digunakan dalam aplikasi wearable. Fotodetektor difabrikasi di atas substrat fleksibel polimida (PI) menggunakan metode spin coating dan dengan pola elektroda interdigitated electrode (IDE) sehingga memungkinkan pembentukan struktur metal-semiconductor-metal (MSM) dengan dua kontak schottky. Penelitian ini mengeksplorasi peningkatan sensitivitas dan efisiensi deteksi UV dengan mengembangkan struktur lapisan dan material semikonduktor ZnO. Hasil karakterisasi arus-tegangan (I–V) dalam skala logaritmik menunjukkan kurva simetris non-linier, dengan threshold voltage ±0,1 V, dark current rendah 0,142 µA, dan photocurrent 5,08 µA di bawah paparan UV, serta dalam kondisi pelengkungan, performa menurun drastis menjadi 33,58 nA. Karakteristik time response menunjukkan rise time 0,83 ms dan fall time 0,34 ms, mengindikasikan respons cepat terhadap cahaya UV. Spektrum UV-Vis Absorbance mengungkapkan serapan di wilayah 290–405 nm, mendukung respons fotolistrik terhadap cahaya UV dan cahaya tampak. Nilai bandgap energy yang diperoleh dari Tauc plot adalah 3,275 eV. Fotodetektor yang telah difabrikasi, kemudian diintegrasikan ke dalam perangkat wearable UV Index Monitor. Fotodetektor UV bertugas mendeteksi radiasi UV dan mengkonversinya menjadi sinyal listrik. Sinyal ini diproses melalui rangkaian pengkondisi sinyal dengan operational amplifier (Op-Amp) yang tersusun menjadi rangkaian penguatan transimpedansi untuk memperkuat sinyal berupa arus yang lemah menjadi tegangan yang dapat diterima mikrokontroler. Mikrokontroler kemudian digunakan untuk membaca sinyal dari fotodetektor melalui ADC (Analog-to-Digital Converter), mengolah data secara real-time, dan menampilkan informasi indeks UV pada antarmuka pengguna. Pengujian menunjukkan bahwa alat mampu memberikan pembacaan indeks UV yang akurat, dengan tingkat kesesuaian regresi 96,9% terhadap data referensi WHO. Namun, setelah digunakan dalam jangka waktu tertentu, performa perangkat menurun akibat degradasi material ZnO dan kerusakan kontak elektroda, sehingga disarankan dilakukan pengujian lanjutan dan perbaikan desain koneksi.
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Ultraviolet (UV) light significantly impacts human skin health, with excessive exposure causing photo-aging and skin cancer. Therefore, developing a wearable UV radiation exposure monitoring system is important. This study aims to develop a zinc oxide-based UV photodetector, which is known for its high sensitivity to UV radiation, for use in wearable applications. This photodetector was fabricated on a flexible polyimide (PI) substrate using the spin coating method, with an interdigitated electrode (IDE) pattern that enables the formation of a metal-semiconductor-metal (MSM) structure with two schottky contacts. This research explores enhancements in sensitivity and UV detection efficiency by optimizing the structure and semiconductor material layers of ZnO. Current–voltage (I–V) characterization in logarithmic scale showed a symmetric nonlinear curve, with a threshold voltage of ±0,1 V, a low dark current of 0.66 µA, and a photocurrent of 7.84 µA under UV exposure. Under mechanical bending, performance dropped significantly to 33.58 nA. The time response characterization revealed a rise time of 0.83 ms and a fall time of 0.34 ms, indicating fast response to UV light. UV-Visible absorbance spectra demonstrated strong absorption in the 290–405 nm range, supporting the photodetector’s sensitivity to UV and visible light. The extracted bandgap energy from the Tauc plot was 3.275 eV. The fabricated photodetector was then integrated into a wearable UV Index Monitor device. The UV photodetector functions to detect UV radiation and convert it into electrical signals. These signals are processed through a signal conditioning circuit with operational amplifiers configured as a transimpedance amplifier to convert weak photocurrent into voltage readable by a microcontroller. The microcontroller reads the signal via an ADC (Analog-to-Digital Converter), processes the data in real-time, and displays the UV index on a user interface. Testing showed that the device was capable of providing accurate UV index readings, with a regression fit of 96.9% compared to WHO reference data. However, after prolonged use, device performance declined due to ZnO material degradation and electrode contact damage. Therefore, further testing and improvements in connector design are recommended.
| Item Type: | Thesis (Other) |
|---|---|
| Uncontrolled Keywords: | Sinar UV, Fotodetektor Fleksibel, Seng Oksida, Wearable, Indeks UV, UV Light, Flexible Photodetector, Zinc Oxide, Wearable, UV Index |
| Subjects: | Q Science > QD Chemistry > QD181.Z6 Zinc oxide T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK152.A75 Electrical engineering--Safety measures T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK7871.674 Detectors. Sensors T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK7872 Electric current converters, Electric inverters. |
| Divisions: | Faculty of Intelligent Electrical and Informatics Technology (ELECTICS) > Electrical Engineering > 20201-(S1) Undergraduate Thesis |
| Depositing User: | Crescentiana Cathlea Jessiena |
| Date Deposited: | 25 Jul 2025 06:52 |
| Last Modified: | 25 Jul 2025 06:52 |
| URI: | http://repository.its.ac.id/id/eprint/121447 |
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