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As a key to simulate electrostatic characteristics of solar cells and implement single-diode model into simulators, a noniterative parameter-extraction method is proposed to determine five parameters of single-diode model. It is straightforwardly derived from the transcend equation set of terminal ${I} - {V}$ equations to overcome the imperfections of poor efficiency in numerical iteration methods, low accuracy in semiempirical approaches, and absence of physical meaning in optimization algorithms. As a result, such a parameter-extraction method actually serves as a useful tool to acquire model parameters, analyze preparing process’ results, and expand practicability of lumped parameter model. [ABSTRACT FROM AUTHOR]

Three-diode lumped-parameter equivalent circuit model conforms to photovoltaic device physics and processes an exact analysis for I – V characteristics of industrial solar cells, because it explains the different leakage current components especially for recombination current resulting from defects or grain boundaries. However, three-diode model’s complete circuit topology leads to complicated transcendental I – V equation without analytical solution so that low computation efficiency limits three-diode model’s applications in photoelectric simulations. In this article, an effective-diode method is proposed to simplify three-diode model, derive accurate and efficient terminal current–voltage solution to three-diode model, and acquire electrostatic characteristics of the solar cells. The calculated values have good agreements with numerical iteration results and experimental data measured from solar cells, respectively. Finally, the effective-diode method performs an important role of solving three-diode model analytically, predicting I – V characteristics of industrial solar cells accurately, and providing three-diode model’s practicability and development in solar cells’ simulations. [ABSTRACT FROM AUTHOR]

A lumped-parameter circuit model is proposed to describe the S-shaped I-V characteristics with current kinks exhibited in perovskite solar cells (PSCs). The physics-based model represents the electrical effect of the electrode contact interface. A Difference-Microvariation (DM) principle is used to derive the explicit solution of the model, which gives accurate and efficient descriptions for the current kinks of PSCs in a single-piece formula. The good agreement between our proposed model and numerical iteration results or reconstructed experimental data proves its validity. We believe that, the improved model can provide optimization direction for device process. Meanwhile, the proposed DM principle can perform as an efficient and serviceable tool to implement the lumped-parameter model compactly into TCAD simulators of PSCs. [ABSTRACT FROM AUTHOR]

A parameter extraction routine for three-diode lumped parameter model of organic solar cells (OSCs) based on particle swarm optimization (PSO) is presented in this letter. In the process of parameter extraction by using PSO, we overcome the problem of encountering locally optimal solutions, where such a problem results from the similar effects of some parameters on ${I} - {V}$ characteristics. Combining with the analytical solution algorithm of OSCs’ three-diode lumped parameter model, our parameter extraction routine can efficiently acquire the accurate fitting parameters to complete simulations for ${I} - {V}$ characteristics. Furthermore, this routine is valid for the different algorithms of the solution to OSCs’ ${I} - {V}$ properties. Finally, we use the experimental data measured from OSCs to verify the parameter extraction routine. As a result, such a parameter extraction routine can perform as an important tool to extract the fitting parameters of OSCs’ lumped parameter model. [ABSTRACT FROM AUTHOR]

A lumped-parameter equivalent circuit model is proposed to simulate the S-shaped current–voltage (${I}$ – ${V}$) characteristics exhibited in organic solar cells. First, we derive an explicit terminal current solution as a function of terminal voltage from the equation set of the three-diode lumped-parameter model proposed by Mazhari. Second, we improved Mazhari’s model to improve the accuracy and developed the explicit solution of our improved model to improve the efficiency. Third, we use the method of least squares, Newton–Raphson root-finding scheme, and experimental data to validate the solutions of Mazhari’s and our models. As a result, owing to high accuracy and efficiency of computation, our explicit calculation scheme, regarded as a useful tool, can help to implement Mazhari’s and our models into photovoltaic device and system simulators in compact format. [ABSTRACT FROM AUTHOR]

An analytical surface-potential-based drain current model of dynamic-depletion (DD) polysilicon (poly-Si) thin-film transistors (TFTs) is proposed in this paper. In the 1-D Poisson equation, total charge density is reformulated by an effective charge density, which allows a closed-form surface potential calculation scheme. Different boundary conditions between partial depletion and full depletion are calculated and unified into one back-gate potential in the DD mode, which allows a unified-form surface potential calculation scheme. Combining with Gauss’s theory, we explicitly solve a closed- and unified-form surface potential of DD poly-Si TFTs. Based on the solution of the surface potential, the drain current is derived analytically from the Pao–Sah integration. Furthermore, our solution is verified by numerical results and experimental data, respectively. As a result, such a model can accurately predict I–V characteristics of DD poly-Si TFTs and provide computational efficiency for TFT process optimization and circuit simulations. [ABSTRACT FROM AUTHOR]

We propose an explicit surface-potential-based direct current (dc) model for fully depleted polysilicon (poly-Si) thin-film transistors (TFTs). Being analytical and explicit, the proposed model is a solid base for compact models of these devices. The essential for our model is the explicit calculation of the surface potential, using the Lambert W function. Subsequently, using the surface potential, we also develop the expressions for charge and current, employing well established approaches, which include integration of carrier’s charge for drain current. Furthermore, the solutions of surface potential and drain current were validated by numerical results and experimental data, respectively. Finally, we discussed in detail about the effects on the surface potential and dc properties from the full depleted poly-Si TFT parameters. As a result, such a model is suitable to be implemented into computer-aided simulations of both device and circuit designs, due to its high computational accuracy and efficiency. [ABSTRACT FROM AUTHOR]

The task of video sequence classification plays a critical role in the development of computer vision. Considering this fact, this letter proposes a novel tensor decomposition method called tensor-driven temporal correlation in which general tensors are used as input for video sequence classification. Because distortion and redundancy may exist in the tensor representations of video sequences, we project the original tensor into subspaces spanned by spatial basis matrices in the proposed formulation. Moreover, to better preserve the temporal smoothness between consecutive slices of the tensor, the basis matrices are jointly learned by introducing an autoregressive model. An experiment on the commonly used Cambridge hand-gesture database demonstrates that our proposed method reaches convergence within a small number of iterations during the training stage and achieves promising results compared with state-of-the-art methods. [ABSTRACT FROM PUBLISHER]