arXiv subjects

Lin Mao

Publications and source records attributed to Lin Mao.

3 recordsLinked to original sources

arXiv2025

Flexible Perovskite/Silicon Monolithic Tandem Solar Cells Approaching 30% Efficiency

Thanks to their excellent properties of low cost, lightweight, portability, and conformity, flexible perovskite-based tandem solar cells show great potentials for energy harvesting applications, with flexible perovskite/c-silicon tandem solar cells particularly promising for achieving high efficiency. However, performance of flexible perovskite/c-silicon monolithic tandem solar cells still greatly lags, due to challenges in simultaneously achieving both efficient photocarrier transport and reliable mitigation of residual stress. Here, we reveal the critical role of perovskite phase homogeneity, for achieving high-efficient and mechanical-stable flexible perovskite/c-silicon heterojunction monolithic tandem solar cells (PSTs) with textured surface. Through ensuring high phase homogeneity, which promotes charge transfer across all facets of the pyramid on the textured substrates and releases the residual stress at the perovskite/c-silicon interface, we demonstrate flexible PSTs with a bending curvature of 0.44 cm-1, and a certified power conversion efficiency of 29.88% (1.04 cm2 aperture area), surpassing all other types of flexible perovskite-based photovoltaic devices. Our results can lead to broad applications and commercialization of flexible perovskite/c-silicon tandem photovoltaics.

cond-mat.mtrl-sci↗

arXiv2024

Spectrality of alternating-sign Moran measures

For $m\geq 2$, let $D_m=\{0,1,\ldots,m-1\}$. For each $k\geq 1$, consider the family of contractions \[ \Phi_k=\{\phi_{k,d}:d\in D_{n_k}\}, \qquad \phi_{k,d}(x)=(-1)^d b_k^{-1}(x+d), \] where $b_k$ and $n_k$ are integers satisfying $b_k\geq n_k\geq 2$. We construct the canonical pullback attractor generated by $\{\Phi_k\}_{k\geq 1}$ and the associated equal-weight Moran measure $\mu$. Suppose that $\{b_k\}_{k\geq 1}$ is bounded and that $n_k$ is even for every $k$. We prove that $\mu$ is spectral if $2\mid b_2,\ n_2\mid 2b_2$, and \(n_k\mid b_k$ for all $k\geq 3$. If, in addition, $4\mid n_k$ for every $k$, then the converse also holds, yielding a complete characterization of spectrality. The proof reduces the associated matrix-valued Fourier recursion to the Fourier transform of an infinite convolution of discrete probability measures. The main new ingredient in the necessity argument is a decomposition method for rational-scale infinite convolutions, in which a spectrum is successively partitioned into congruence classes.

math.FA↗

arXiv2023

High precision atom interferometer-based dynamic gravimeter measurement by eliminating the cross-coupling effect

A dynamic gravimeter with an atomic interferometer (AI) can perform absolute gravity measurements with high precision. AI-based dynamic gravity measurement is a type of joint measurement that uses AI sensors and a classical accelerometer. The coupling of the two sensors may degrade the measurement precision. In this study, we analyzed the cross-coupling effect and introduced a recovery vector to suppress this effect. We improved the phase noise of the interference fringe by a factor of 1.9 by performing marine gravity measurements using an AI-based gravimeter and optimizing the recovery vector. Marine gravity measurements were performed, and high gravity measurement precision was achieved. The external and inner coincidence accuracies of the gravity measurement are 0.42 mGal and 0.46 mGal, which were improved by factors of 4.18 and 4.21 by optimizing the cross-coupling effect.

physics.app-ph↗