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  • Ph.D. (1994)

    Electrical Engineering- Electronics (Optoelectronics)

    Electrical Engineering, Kyoto, Kyoto, Japan

  • M.Sc. (1990)

    Electrical Engineering- Electronics

    Electrical Engineering, Tarbiat Modares University, Tehran, Iran

  • B.Sc. (1986)

    Electrical Engineering-Electronics

    Electrical Engineering, Sharif University of Technology, Tehran, Iran

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Vahid Ahmadi received the PhD degree in electronic engineering from Kyoto University, Japan, in 1994. He is a Professor in electronic engineering at Tarbiat Modares University (TMU), Tehran, Iran. He is a senior member of IEEE and the Vice Chair of IEEE IRAN Section. He was the Head of the Semiconductor Department of Laser Research Centre, Tehran, 1994-2006. He was the Head of the Electrical and Computer Engineering Department of TMU, during 2006?2008. He was the technical and scientific Chair of 13th Iranian Conf. on Optics and Photonics, 2007, and the general Chair of the 16th Iranian Conference on Electrical Engineering (ICEE2008), 2008. He is the member of the Founders-Board of Optics and Photonics Society of Iran, the editorial board of International Journal of Information Communication Technology Research (IJICTR). He has also been the Editor-in-chief of Modares Journal of Electrical Engineering since 2012. He is currently the Chair of Optoelectronics and Nano-photonics Research Group, and the Head of Nano-Optoelectronic Laboratory at TMU. He is also Advisor to Iran Minister of Science, Research and Technology Head of National Research Institute for Science Policy.

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Curriculum Vitae (CV)

Charge transfer balancing of planar perovskite solar cell based on a low cost and facile solution-processed CuO x as an efficient hole transporting layer

Marzieh Makenali, Iraj Kazeminezhad, Vahid Ahmadi, Farzaneh Arabpour Roghabadi
Journal PaperJournal of Materials Science: Materials in Electronics , 2021 January 2, {Pages 14-Jan }

Abstract

Planar perovskite solar cells are known for their ease of fabrication and considerable efficiency. Hole transport layer in these cells is however mostly either expensive organic spiro-OMeTAD or hydrophilic PEDOT: PSS polymer which reduces cell lifespan due to its acidic nature. Copper oxide, on the other hand, is a non-toxic inorganic alternative. It can be synthesized through a facile solution-based process, requiring no vacuum system or N2 glovebox, which makes it conveniently adaptable to large-scale production. Inverted planar perovskite solar cells with CuOx as hole transport layer were studied. To balance the charge transfer in the device and avoid the charge accumulation in the bulk and interfaces, CuOx layer was deposit

The Future of Hybrid and Inorganic Perovskite Materials: Technology Forecasting

K Oniy Aghmiuni, F Arabpour Roghabadi, H Rezvani, M Alidaei, M Falahi, ...
Journal Paper , , {Pages }

Abstract

Efficiency improvement of perovskite solar cells by charge transport balancing using length tunable ZnO nanorods and optimized perovskite morphology

M Makenali, I Kazeminezhad, FA Roghabadi, V Ahmadi
Journal Paper , , {Pages }

Abstract

Materials and structures engineering of sun-light absorbers for efficient direct solar steam generation

S Karami, FA Roghabadi, M Maleki, V Ahmadi, SM Sadrameli
Journal Paper , , {Pages }

Abstract

Recent Progress on Metal Halide Perovskite Solar Minimodules

Z Yang, Z Liu, V Ahmadi, W Chen, Y Qi
Journal Paper , , {Pages }

Abstract

Highly sensitive crumpled 2D material-based plasmonic biosensors

V Faramarzi, V Ahmadi, MT Hwang, P Snapp
Journal Paper , , {Pages }

Abstract

Highly Efficient Solar Steam Generators Based on Multicore@ Shell Nanostructured Aerogels of Carbon and Silica as the Light Absorber− Heat Insulator

S Karami, F Arabpour Roghabadi, F Pashaei Soorbaghi, V Ahmadi, ...
Journal Paper , , {Pages }

Abstract

Design and Simulation of Graphene/2D Interlayer Surface Plasmon Resonance Biosensor Based on Ellipsometry Method

MJ Haji Najafi, V Ahmadi, SM Hamidi
Journal Paper , , {Pages }

Abstract

Engineered nano-sphere array of gold-DNA core–shells and junctions as opto-plasmonic sensors for biodetection

N Osanloo, V Ahmadi, M Naser-Moghaddasi, E Darabi
Journal Paper , , {Pages }

Abstract

Asymmetric silicon–polymer hybrid waveguide for second-harmonic generation based on modal phase matching

Babak Janjan, Vahid Ahmadi, Mehdi Miri, Davood Fathi
Journal PaperJOSA B , Volume 37 , Issue 2, 2020 February 1, {Pages 376-381 }

Abstract

We propose and design a nonlinear-polymer-filled asymmetric silicon slot waveguide (SSW) for efficient second-harmonic generation. The distinct modal dispersion of the designed asymmetric SSW is used to achieve phase matching between the zeroth-order waveguide mode at the fundamental frequency ($\lambda = {3.1}\,\,\unicode{x00B5}{\rm m}$λ=3.1?m) and the second-order mode at the second-harmonic frequency ($\lambda = {1.55}\,\,\unicode{x00B5}{\rm m}$λ=1.55?m). Simulation results show a conversion efficiency of P_2ω/P_ω=32% with only 10 mW pump power. This high efficiency is a consequence of introducing an asymmetry in the SSW which not only could provide modal phase matching but also preserves high modal overlap between the interacting wa

High-brightness Perovskite Light-emitting Diodes Using a Printable Silver Micro-flake Contact

Masoud Payandeh, Vahid Ahmadi, Farzaneh Arabpour Roghabadi, Pariya Nazari, Fatemeh Ansari, Philipp Brenner, Rainer Baeuerle, marius jakoby, Uli Lemmer, Ian A Howard, Bryce Sydney Richards, Ulrich Wilhelm Paetzold, Bahram Abdollahi Nejand
Journal PaperACS Applied Materials & Interfaces , 2020 January 31, {Pages }

Abstract

Achieving efficient devices while maintaining a high fabrication yield is a key challenge in the fabrication of solution-processed, perovskite-based light-emitting diodes (PeLEDs). In this respect, pinholes in the solution-processed perovskite layers are a major obstacle. These are usually mitigated using organic electron-conducting planarization layers. However, these organic interlayers are unstable under applied bias in air, and suffer from limited charge-carrier mobility. In this work, we present a high brightness p-i-n PeLED based on a novel blade-coated silver micro-flake (SMF) rear electrode, which allows for a low-cost and high performance nanocrystalline ZnO inorganic electron transporting layer to be used. This novel SMF contact i

Facile synthesis of durable perovskite quantum dots film with near unity photoluminescence quantum yield for efficient perovskite light emitting diode

Farzaneh Arabpour Roghabadi, Vahid Ahmadi
Journal PaperApplied Surface Science , 2020 January 23, {Pages 145513 }

Abstract

In this work, a bright uniform PSK QDs film is synthesized in-situ using an amorphous polymer and optimizing the stoichiometry. The in-situ formed QDs film grown in the presence of poly(vinylpyrrolidone) chains shows a photoluminescence quantum yield (PLQY) as high as 98% even under low light intensities (0.01mW/cm2) with a long shelf lifetime of up to 2 years under ambient light (nanocrystals retain 100% of the initial PLQY). The near unity PLQY is due to the passivation of the surface defects of the PSK QDs by the Lewis base pyrrolidone groups of the polymer chain. Further, the QDs film shows higher thermal stability that increases by a factor of more than 5 compared to the bulk film. High efficient green perovskite light emitting diodes

Durable Perovskite UV Sensor Based on Engineered Size-Tunable Polydimethylsiloxane Microparticles Using a Facile Capillary Microfluidic Device from a High-Viscosity Precursor

Ahdieh Amjadi, Mahdi Salami Hosseini, Tahereh Ashjari, Farzaneh Arabpour Roghabadi, Vahid Ahmadi, Kiyumars Jalili
Journal PaperACS Omega , 2020 January 7, {Pages }

Abstract

In this work, size-tunable polydimethylsiloxane (PDMS) microparticles are fabricated from a high-viscosity oil phase using a facile coflowing capillary microfluidic device and optimized aqueous phase composition. The dispersity of the microparticle size is tuned by engineering of the viscosity of the continuous phase and flow rate ratio that leads us to achieve monodisperse microparticles. Regarding the high potential of the PDMS microparticles for optical applications, efficient environmentally durable perovskite-based UV sensors are fabricated employing the designed size-tunable microparticles. Surprisingly, the UV sensors comprising CH3NH3PbBr3 perovskite quantum dots as UV-sensitive nanocrystals embedded in transparent PDMS microparticl

Magnetite as Inorganic Hole Transport Material for Lead Halide Perovskite-Based Solar Cells with Enhanced Stability

Fatemeh Ansari, Masoud Salavati-Niasari, Omid Amiri, Noshin Mir, Bahram Abdollahi Nejand, Vahid Ahmadi
Journal PaperIndustrial & Engineering Chemistry Research , 2020 January 3, {Pages }

Abstract

A low-cost and stable perovskite solar cell using solution-processed nanostructured Fe3O4 as a potential hole transport layer (HTL) was reported for the first time. The Hall effect measurement performed on Fe3O4 film showing hole-type carriers with a mobility of 0.269 cm2 V–1 s–1 confirmed that Fe3O4 could be a potential hole-transporting material (HTM) candidate for perovskite solar cells. This value is higher than the reported one for other inorganic HTMs such as CuSCN (0.01–0.1 cm2 V–1 s–1). The prepared device using Fe3O4 shows a maximum power conversion efficiency (PCE) of 15.42% and long-term durability up to 30 days. This inorganic HTM is introduced as a strong and low-cost substitution to the expensive complex materials in

Prolonged Lifetime of Perovskite Solar Cells Using a Moisture-Blocked and Temperature-Controlled Encapsulation System Comprising a Phase Change Material as a Cooling Agent

Nasibeh Mansour Rezaei Fumani, Farzaneh Arabpour Roghabadi, Maryam Alidaei, Seyed Mojtaba Sadrameli, Vahid Ahmadi, Farhood Najafi
Journal PaperACS omega , Volume 5 , Issue 13, 2020 April 7, {Pages 7106 }

Abstract

Although the power conversion efficiency of perovskite solar cells (PSCs) reached up to 25% that made them comparable to the commercial solar cells, they are facing issues toward commercialization, especially their short lifetime. Remarkably, the most important key factors that regulate the durability of the devices are moisture, light, and heat. In this work, prolonging the device lifetime is focused by designing a flexible moisture-blocked and temperature-controlled encapsulation system. In this regard, a thermally adjusted phase change material is embedded in a polymer encapsulation layer to avoid the moisture diffusion, rapid temperature fluctuation, and undesired crystalline phase change of the perovskite layer in the PSCs under the op

Prolonged Lifetime of Perovskite Solar Cells Using a Moisture-Blocked and Temperature-Controlled Encapsulation System Comprising a Phase Change Material as a Cooling Agent

Nasibeh Mansour Rezaei Fumani, Farzaneh Arabpour Roghabadi, Maryam Alidaei, Seyed Mojtaba Sadrameli, Vahid Ahmadi, Farhood Najafi
Journal PaperACS omega , Volume 5 , Issue 13, 2020 March 30, {Pages 7106-7114 }

Abstract

Although the power conversion efficiency of perovskite solar cells (PSCs) reached up to 25% that made them comparable to the commercial solar cells, they are facing issues toward commercialization, especially their short lifetime. Remarkably, the most important key factors that regulate the durability of the devices are moisture, light, and heat. In this work, prolonging the device lifetime is focused by designing a flexible moisture-blocked and temperature-controlled encapsulation system. In this regard, a thermally adjusted phase change material is embedded in a polymer encapsulation layer to avoid the moisture diffusion, rapid temperature fluctuation, and undesired crystalline phase change of the perovskite layer in the PSCs under the op

Ultrashort optical pulse polarization rotator based on azimuth angle rotation in semiconductor optical amplifier

Ahvan Sharifi, Mohammad Razaghi, Vahid Ahmadi
Journal PaperOptical Engineering , Volume 59 , Issue 3, 2020 March , {Pages 036108 }

Abstract

For the first time, a dynamic model is used to design all-optical polarization rotator for ultrashort pulse in semiconductor optical amplifier (SOA). When 200?fs probe and pump pulses co-propagate in SOA, the azimuth angle of probe polarization is rotated by pump energy due to SOA nonlinearities. As a result of azimuth angle rotation (AAR) phenomenon, the state of polarization (SOP) of probe pulse also rotates. In addition to the pump energy, AAR also depends on the input probe pulse characteristics and the SOA bias current. The input probe characteristics include its input energy level, input Stokes vector, and input degree of polarization. The results of our research indicate that the output probe azimuth angle can be rotated up to 113?de

Quasi-Phase Matched Second Harmonic Generation in Plasmonic–Organic Hybrid Structures

Babak Janjan, Vahid Ahmadi, Davood Fathi
Journal PaperJournal of Lightwave Technology , Volume 38 , Issue 6, 2020 March 15, {Pages 1391-1399 }

Abstract

In this article, we propose the design and analyze a plasmonic-organic-hybrid (POH) waveguide structure for efficient forward and backward second harmonic generation (SHG) to bridge the mid-infrared (IR) to near-IR. The required phase matching is satisfied by quasi-phase matching (QPM) technique through periodically altering the material of the metal-insulator-metal slot region between a nonlinear polymer (with second-order nonlinear coefficient of χ^(2) ≠ 0) and Al_2O_3 (with χ^(2) = 0) leading to modulation of χ^(2) coefficient along the propagation direction. The strong field confinement offered by surface plasmon polaritons (SPPs) significantly enhances the normalized efficiency up to 1.75 ? 10^6 W^−1cm^−2 in the case of backwa

Composite polymer/perovskite quantum dots luminescent material

Journal Paper , 2020 May 21, {Pages }

Abstract

A composite luminescent material synthesized by forming a precursor solution, forming a perovskite quantum dot/polymer composite by transferring the precursor solution onto a first substrate, and forming a composite luminescent material by coating the perovskite quantum dot/polymer composite with a polydimethylsiloxane (PDMS) solution. An exemplary precursor solution may be formed by obtaining a first solution by dissolving a polymer in a first organic solvent, obtaining a second solution by mixing an inorganic metal halide solution and an organic amine halide solution, and mixing the first solution and the second solution.

Enhanced performance of CH3NH3PbI3 perovskite solar cells via interface modification using phenyl ammonium iodide derivatives

Farzaneh S Ghoreishi, Vahid Ahmadi, Reza Poursalehi, Mahmoud SamadPour, Malin B Johansson, Gerrit Boschloo, ErikM J Johansson
Journal PaperJournal of Power Sources , Volume 473 , 2020 October 15, {Pages 228492 }

Abstract

Interface modification in perovskite solar cells is a key factor for achieving high power conversion efficiency by suppressing electron-hole recombination and accelerating charge carrier extraction. Here, we use a series of phenyl ammonium derivatives, phenyl ammonium iodide (PAI), benzyl ammonium iodide (BAI), and phenyl ethyl ammonium iodide (PEAI), to modify the interface between methylammonium lead triiodide (MAPbI3) perovskite and Spiro-OMeTAD as a hole transport layer in solar cell devices. The structural and optical properties of the perovskite films are studied and the results reveal the formation of two-dimensional perovskite interfacial layers on the surface of the MAPbI3 film modified with PEAI and BAI whereas the MAPbI3 layer mo

Current Teaching

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Teaching History

  • MS.c.

    Optoelectronics

  • 1981
    saeed, pahlavan
  • 2018
    Ahmadi, Zahra
    Design and fabrication of MMF/MMF/MMF based Mach- Zehnder interferometer fiber sensor for CRP and Glucose detection
  • 2018
    Taghilou, Masoomeh
  • 2018
    Momeni, Fateme
  • 2019
    Pakzad moqhaddam, Seyed mojtaba
  • 2017
    Vahabzad, Fereshteh
    perovskite light emitting diode stability enhancement using two dimensional and quasi two dimensional structures

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