Malaysian Journal of Analytical Sciences Vol 19 No 6 (2015): 1256 - 1263

 

 

 

Si FUNCTIONALIZATION WITH DYE MOLECULAR AS LIGHT-HARVESTING MATERIAL

 

(Pemfungsian Silikon dengan Molekul Pewarna sebagai Bahan Penuaian Cahaya)

 

Nurul Aqidah Mohd Sinin, Mohd Adib Ibrahim*, Mohd Asri Mat Teridi, Norasikin Ahmad Ludin,

Suhaila Sepeai, Kamaruzzaman Sopian

 

Solar Energy Research Institute (SERI),

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

 

*Corresponding author: mdadib@ukm.edu.my

 

 

Received: 5 February 2015; Accepted: 29 September 2015

 

 

Abstract

The surface plays an important role in thin silicon solar cells, especially with regard to the surface state and interface electronic properties that influence the electron and hole to recombine. In order to keep the recombination loss at a tolerable minimum and avoid an unacceptably large efficiency loss when moving towards thinner silicon materials, the surface must be electronically wellpassivated. Passivation is the most significant step for the functionalization of silicon. In this study, Si functionalization with a dye molecule might increase the absorption of light that acts as light-harvesting material on the silicon surface. Two types of dye molecular were used; DiL (λ_peak = 549 nm) and DiO (λ_peak = 484 nm). Both dyes were deposited using a spin-coating technique. These dye layers on the silicon surface were characterized using a Kelvin probe (KP) and photoluminescence (PL) spectroscopy. A different mechanism of slow charge trapping and detrapping was observed using KP measurement. A lifetime decay was observed that indicated a slow process of charge detrapping, owing to light trapping inside the dye/SiNW interface, with a slow process for an equilibrium to establish between the surface states and the space charge region. An average lifetime of the entire fluorescence decay process was recorded at about 1.24 ns (DiO) and 0.22 ns (DiL), using PL spectroscopy. We show conclusively that these two types of dye can be used as light absorbers, in order to improve the surface properties of the silicon.

 

Keywords: Si functionalization, dye molecular, light harvesting, Kelvin probe, lifetime

 

Abstrak

Permukaan memainkan peranan penting dalam sel-sel suria silikon nipis terutama keadaan permukaan dan ciri-ciri elektronik yang mempengaruhi elektron dan lohong untuk bergabung semula. Untuk mengekalkan kehilangan penggabungan semula itu sekurang-kurangnya boleh diterima dan mengelakkan kehilangan kecekapan apabila bergerak ke arah bahan silikon nipis, permukaan mesti secara elektronik juga dipasifkan. Pemasifan adalah langkah yang paling penting untuk pemfungsian silikon. Dalam kajian ini, pemfungsian silicon dengan molekul pewarna mungkin meningkatkan penyerapan cahaya yang bertindak sebagai bahan penuaian cahaya pada permukaan silikon. Dua jenis molekul pewarna telah digunakan; DiL (λ_puncak = 549 nm) dan DiO (λ_puncak = 484nm). Kedua-dua pewarna telah dimendapkan menggunakan teknik salutan putaran. Permukaan silikon telah dicirikan menggunakan Kelvin probe (KP) dan spektroskopi kefotopendarcahayaan (PL). Satu mekanisma yang berbeza untuk penjeratan dan penyahjeratan cas yang perlahan telah diperhatikan menggunakan pengukuran Kelvin probe. Pereputan seumur hidup diperhatikan dan menunjukkan bahawa proses penyahjeratan cas yang perlahan akibat proses memerangkap cahaya di dalam pewarna/muka SiNW yang lambat untuk keseimbangan di antara keadaan permukaan dan rantau cas ruang. Satu jangka hayat purata proses pereputan pendarfluor keseluruhan telah mencatatkan kira-kira 1.24 ns (DiO) dan 0.22 ns (DiL) menggunakan spektroskopi PL. Kami menunjukkan dengan pasti bahawa kedua-dua jenis pewarna boleh digunakan sebagai penyerap cahaya untuk memperbaiki sifat-sifat permukaan silikon.

 

Kata kunci: pemfungsian silikon, molekul pewarna, penuaian cahaya, Kelvin probe, jangka hayat

 

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