Perovskite quantum dots have the advantages of half peak width, high fluorescence quantum yield, and adjustable spectral range. The Perovskite QDs have been widely used in display, lighting, lasers, solar cells, photodetectors and other fields. 

Structure of Perovskites Quantum Dots

Halide perovskite nanocrystals have a cubic crystal structure with the chemical formula A⁺Pb²⁺X_^-3. They can be classified as organic-inorganic hybrids, where A is an organic cation such as methylammonium (MA) or formamide (FA), or completely inorganic (A=Cs), while X is a halogen (Cl, Br or I). Due to the lack of volatile organic compounds, fully inorganic nanocrystals tend to have better stability and higher PLQY (>90%) than organic-inorganic hybrid materials. Mixed halide perovskites can also be produced, where X can be a mixture of Cl/Br or Br/I.

Preparation Methods

1. Template Method

PNCs were first successfully prepared in 2012 by Akihiro Kojima et al. MAPbBr₃ NCs were successfully synthesized by the template method, i.e., using porous alumina films as templates in a rapid self-assembly manner, and were able to emit strong green light at a wavelength of 523 nm at an excitation wavelength of 350 nm.

2. Thermal Injection Method

Thermal injection is the most commonly used method for the synthesis of perovskite nanocrystals. The inorganic perovskite CsPbX₃ (X = Cl, Br, I) NCs were successfully prepared by hot injection method under nitrogen atmosphere, and the size of CsPbX₃ NCs was adjusted by repeatedly changing the halogen ratio and controlling the reaction temperature (140-200℃), and the emission spectra were finally obtained in the range of 400-700 nm. The CsPbX₃ NCs with different sizes and compositions were obtained.

3. Ligand-Assisted Reprecipitation Method (LARP)

The ligand-assisted reprecipitation method involves dissolving the reactants MABr and PbBr₂, as well as the surface modifiers octylamine (OcAm) and oleic acid (OA) in N,N-dimethylformamide (DMF) to form a reaction precursor solution, and then taking a certain amount of the reaction precursor solution and dropping it into toluene, centrifuging it, and evaporating the supernatant to obtain MAPbBr₃ NCs with a size of only 3.3 nm and a PLQY of 70%. MAPbBr₃ NCs with a size of 3.3 nm and a PLQY of 70%.

4. Other Methods

Ultrasonic Method
Solvothermal Method
Microwave-Assisted Method
Ball Milling Method