Yasser Hassan

• PhD in the Applied Chemistry from the University of Toronto, Canada
• Research Assistant at University of Toronto

The electrochemical reduction of carbon dioxide (eCO2RR) has become a very promising pathway that can be used in the transformation of CO2 to important chemical products and, thus, is one of the mitigations of climate change and will contribute toward sustainable chemical production. This review aims at presenting the importance of Nuclear Magnetic...

One of the most significant challenges of luminescent materials is the thermal quenching (TQ) at high temperature. Understanding the correlation between crystal structure variation and photoluminescence (PL) quenching is significant to achieve anti‐thermal quenching (anti‐TQ) phosphors. Herein, we unveil a universal principle governing switchable T...

One of the most significant challenges of luminescent materials is the thermal quenching (TQ) at high temperature. Understanding the correlation between crystal structure variation and photoluminescence (PL) quenching is significant to achieve anti‐thermal quenching (anti‐TQ) phosphors. Herein, we unveil a universal principle governing switchable T...

The addition of aqueous hydrohalic acids (HX, X = F, Cl, Br) during the synthesis of colloidal quantum dots (QDs) is now widely employed to achieve high‐quality QDs. However, this reliance on the use of aqueous solutions is incompatible with oxygen‐ and water‐sensitive precursors such as those used in the synthesis of Te‐alloyed ZnSe QDs. Herein, w...

Blue perovskite light-emitting diodes (LEDs) have shown external quantum efficiencies (EQEs) of more than 10%; however, devices that emit in the true blue-those that accord with the emission wavelength required for Rec. 2100 primary blue-have so far been limited to EQEs of ~6%. We focused here on true blue emitting CsPbBr3 colloidal nanocrystals (c...

III-V colloidal quantum dots (CQDs) are promising materials for optoelectronic applications, for they avoid heavy metals while achieving absorption spanning the visible to the infrared. However, the covalent nature of III-V CQDs requires the development of new passivation strategies to fabricate conductive CQD solids for optoelectronics: we show he...

Lead halide perovskites are promising semiconductors for light-emitting applications because they exhibit bright, bandgap-tunable luminescence with high colour purity1,2. Photoluminescence quantum yields close to unity have been achieved for perovskite nanocrystals across a broad range of emission colours, and light-emitting diodes with external qu...

We analyse nucleation-controlled nanocrystal growth in a solution containing surface-binding molecular ligands, which can also nucleate compact layers on the crystal surfaces. We show that if the critical nucleus size for ligands is larger and the nucleation barrier is lower than those for crystal atoms, the ligands nucleate faster than the atoms o...

Lead halide perovskite nanocrystals (NCs) are promising for applicationsin lightemitting devices owing to astrong emission spectrum that is tunable throughout the visible region by altering halide composition. However,in mixed-halide perovskite systems photoinduced migrationdrives formation of halide-segregateddomains, altering the emission spectru...

ArXiv: https://arxiv.org/abs/1905.09073 Previous theoretical calculations show azetidinium has the right radial size to form a 3D perovskite with lead halides [1], and has been shown to impart, as the A-site cation of ABX3 unit, beneficial properties to ferroelectric perovskites [2]. However, there has been very limited research into its use as th...

Previous theoretical calculations show azetidinium has the right radial size to form a 3D perovskite with lead halides [1], and has been shown to impart, as the A-site cation of ABX3 unit, beneficial properties to ferroelectric perovskites [2]. However, there has been very limited research into its use as the cation in lead halide perovskites to da...

Metal halide perovskites are promising candidates for use in light emitting diodes (LEDs), due to their potential for colour tuneable and high luminescence efficiency. While recent advances in perovskite-based light emitting diodes have resulted in external quantum efficiencies exceeding 12.4 % for the green emitters, and infrared emitters based on...

We report the synthesis and characterization of cadmium selenide nanocrystals with electro-active ligands directly attached to the surface. The conventional surfactant-assisted synthesis yields nanocrystals with surfaces functionalized with insulating organic ligands. These insulating ligands act as a barrier for charge transport between nanocrysta...

Colloidally stable suspensions of lead halide perovskite nanocrystals are prepared from high quality lead halide nanocrystal seeds. Perovskite nanocrystals with different layered crystal structures are reported. These systems are well suited for investigations of the intrinsic photophysics and spectroscopy of organic-inorganic metal halide perovski...

Linker-free TiO2/CdSe hybrid nanorods (NRs) were prepared by growing CdSe QDs in the presence of TiO2 NR seeds using seeded–growth type colloidal injection approach. TEM studies revealed the abundant formation of anatase TiO2 NRs with different lengths. We found that the as-prepared TiO2 seeds determined the morphology of TiO2/CdSe NRs. The photoph...

Quantum dots (QDs) demonstrate a wide range of desirable size- and shape-dependent properties that benefit their application as probes for biological imaging in vitro and in vivo, in molecular diagnostics and for device-level integration (e.g., in light emitting diodes, displays, solar cells and sensors). While available for more than 20 years, the...

When 2-propanol is added to a chloroform solution containing a mixture of CdSe quantum dots (QDs) plus a polystyrene-block-poly(4-vinylpyridine) diblock copolymer (PS404-b-P4VP76, the subscripts refer to the degree of polymerization), the block copolymer assembles into uniform 40 nm diameter spherical micelles with a PS core and a thin P4VP corona...

We present a multiphase microfluidic (MF) platform for on-chip preparation of high quality nanocrystals (NCs) using a novel multi-stage growth strategy. To reduce the axial dispersion along the flow direction, gas-liquid segmented flow was used as the flow format. We used a relatively short (0.65 m long) silicon-based MF device in the multi-pass NC...

Coherent superpositions among eigenstates are of interest in fields as diverse as photosynthesis and quantum computation. In this report, we used two-dimensional electronic spectroscopy (2D ES) to measure the decoherence time of a superposition of the two lowest-energy excitons in colloidal CdSe nanocrystals (cubic phase) in solution at room temper...

Poly(styrene-b-4-vinylpyridine) diblock copolymersPS404-b-P4VP76 and PS317-b-P4VP76 (the subscripts indicate the degree of polymerization) self-assemble into spherical “crew-cut” micelles with a PS core and P4VP corona when prepared in a mixture of chloroform and 2-propanol. When the micelles are formed in the presence of quantum dots (QDs), the na...

Poly(styrene-b-4-vinylpyridine) (PS404-b-P4VP76, where the subscripts refer to the number-averaged degree of polymerization) forms spherical crew-cut micelles with a PS core and a P4VP corona when 2-propanol is added to a solution of the polymer in chloroform. When the CHCl3 solution also contains CdSe quantum dots, hybrid micelles form with the QD...