Passivation of defects in perovskite materials for improved solar cell efficiency and stability

Semiconductor devices, and methods of forming the same, include a cathode layer, an anode layer, and an active layer disposed between the cathode layer and the anode layer, wherein the active layer includes a perovskite layer. A passivation layer is disposed directly on a surface of the active layer between the cathode layer and the active layer, the passivation layer including a layer of material that passivates both cationic and anionic defects in the surface of the active layer

PASSIVATION OF DEFECTS IN PEROVSKITE MATERIALS FOR IMPROVED SOLAR CELL EFFICIENCY AND STABILITY

Semiconductor devices , and methods of forming the same , include a cathode layer , an anode layer , and an active layer disposed between the cathode layer and the anode layer , wherein the active layer includes a perovskite layer . A passivation layer is disposed directly on a surface of the active layer between the cathode layer and the active layer , the passivation layer including a layer of material that passivates both cationic and anionic defects in the surface of the active layer

INSULATING TUNNELING CONTACT FOR EFFICIENT AND STABLE PEROVSKITE SOLAR CELLS

Perovskite-based photoactive devices, such as solar cells, include an insulating tunneling layer inserted between the perovskite photoactive material and the electron collection layer to reduce charge recombination and concomitantly provide water resistant properties to the device

A New Framework for Fast Homomorphic Matrix Multiplication

Homomorphic Encryption (HE) is one of the mainstream cryptographic tools used to enable secure outsourced computation. A typical task is secure matrix computation. Popular HE schemes are all based on the problem of Ring Learning with Errors (RLWE), where the messages are encrypted in a ring. In general, the ring dimension should be large to ensure security, which is often larger than the matrix size. Hence, exploiting the ring structure to make fast homomorphic matrix computation has been an important topic in HE. In this paper, we present a new framework for encoding a matrix and performing multiplication on encrypted matrices. The new framework requires fewer basic homomorphic operations for matrix multiplication. Suppose that the ring dimension is $n$ and the matrix size is $d\times d$ with $d= n^{\rho}$. (1) In the compact case where $\rho \leq \frac{1}{3}$, the multiplication of two encrypted matrices requires $\tilde{O}(1)$ basic homomorphic operations, which include plaintext-ciphertext multiplications, ciphertext-ciphertext multiplications, and homomorphic Galois automorphisms. (2) In the large sized case where $\rho> \frac{1}{3}$, our new method requires $O\big(d^{(1 - \frac{1}{3\rho})\cdot \log_2 7 }\big)$ basic homomorphic operations, which is better than all existing methods. In addition, the new framework reduces the communication cost, since it requires fewer key-switching keys. The number of key-switching keys is reduced from $O(d)$ to $O(\log d)$

Water-Soluble 3D Covalent Organic Framework that Displays an Enhanced Enrichment Effect of Photosensitizers and Catalysts for the Reduction of Protons to H2.

Covalent organic frameworks (COFs) are emerging porous polymers that have 2D or 3D long-range ordering. Currently available COFs are typically insoluble or decompose upon dissolution, which remarkably restricts their practical implementations. For 3D COFs, the achievement of noninterpenetration, which maximizes their porosity-derived applications, also remains a challenge synthetically. Here, we report the synthesis of the first highly water-soluble 3D COF (sCOF-101) from irreversible polymerization of a preorganized supramolecular organic framework through cucurbit[8]uril (CB[8])-controlled [2 + 2] photodimerization. Synchrotron X-ray scattering and diffraction analyses confirm that sCOF-101 exhibits porosity periodicity, with a channel diameter of 2.3 nm, in both water and the solid state and retains the periodicity under both strongly acidic and basic conditions. As an ordered 3D polymer, sCOF-101 can enrich [Ru(bpy)3]2+ photosensitizers and redox-active polyoxometalates in water, which leads to remarkable increase of their photocatalytic activity for proton reduction to produce H2