Analisis arus-voltan bagi pengubahsuaian proses fabrikasi sel suria silikon jenis-p ke atas wafer silikon jenis-n

Sel suria adalah peranti semikonduktor yang menukar tenaga matahari kepada tenaga elektrik. Sel suria generasi pertama terdiri dari sel suria silikon (Si). Pada masa ini, hampir 90% daripada pasaran pengeluaran fotovolta (PV) adalah berdasarkan wafer Si. Ini disebabkan oleh kecekapan dan ketahanan yang tinggi serta jangka hayat yang lama iaitu selama 30 tahun. Proses pemfabrikasian piawai bagi sel suria Si dimulakan dengan proses pencucian dan penteksturan wafer Si, difusi Fosforus untuk pembentukan pemancar, pembentukan elektrod atas dan bawah melalui proses cetakan skrin dan proses pembakaran yang melengkapkan fabrikasi sel suria. Dalam industri, proses piawai ini dilakukan pada wafer Si jenis-p. Wafer jenis-n pula mempunyai potensi yang tinggi untuk menghasilkan sel suria Si yang berkecekapan tinggi. Namun, proses untuk menghasilkan sel suria silikon atas Si wafer jenis-n melalui proses yang lebih rumit dan lama seperti dua peringkat proses difusi menjadikan wafer jenis-p digunakan secara meluas kerana dapat merendahkan kos pemfabrikasian. Dalam penyelidikan ini, analisis bagi arus-voltan bagi sel suria Si jenis-n yang difabrikasi menggunakan adaptasi proses fabrikasi piawai bagi wafer Si jenis-p akan dibincangkan. Daripada kajian simulasi menggunakan perisian PC1D, didapati bahawa kecekapan bagi sel suria jenis-p dan jenis-n yang difabrikasi dengan kaedah yang sama adalah 19.63% dan 20.16%. Manakala keputusan eksperimen menunjukkan kecekapan sebanyak 9.44% dan 5.51% bagi sel suria jenis-p dan jenis-n

In-depth investigation of spin-on doped solar cells with thermally grown oxide passivation

Solar cell industrial manufacturing, based largely on proven semiconductor processing technologies supported by significant advancements in automation, has reached a plateau in terms of cost and efficiency. However, solar cell manufacturing cost (dollar/watt) is still substantially higher than fossil fuels. The route to lowering cost may not lie with continuing automation and economies of scale. Alternate fabrication processes with lower cost and environmental-sustainability coupled with self-reliance, simplicity, and affordability may lead to price compatibility with carbon-based fuels. In this paper, a custom-designed formulation of phosphoric acid has been investigated, for n-type doping in p-type substrates, as a function of concentration and drive-in temperature. For post-diffusion surface passivation and anti-reflection, thermally-grown oxide films in 50–150-nm thickness were grown. These fabrication methods facilitate process simplicity, reduced costs, and environmental sustainability by elimination of poisonous chemicals and toxic gases (POCl3, SiH4, NH3). Simultaneous fire-through contact formation process based on screen-printed front surface Ag and back surface through thermally grown oxide films was optimized as a function of the peak temperature in conveyor belt furnace. Highest efficiency solar cells fabricated exhibited efficiency of ∼13%. Analysis of results based on internal quantum efficiency and minority carried measurements reveals three contributing factors: high front surface recombination, low minority carrier lifetime, and higher reflection. Solar cell simulations based on PC1D showed that, with improved passivation, lower reflection, and high lifetimes, efficiency can be enhanced to match with commercially-produced PECVD SiN-coated solar cells. Keywords: Crystalline Si solar cells, Phosphoric acid spin-on doping, Screen printing, Thermal oxide passivatio