Intermediate Layers in Tandem Organic Solar Cells

Tandem structures can boost the efficiency of organic solar cell to more than 15%, compared to the 10% limit of single layer bulk heterojunction devices. Design and fabricating of intermediate layers plays a very important role to achieve high device performance. This article will review the main experimental progresses of tandem organic solar cells, and focus on the intermediate layers (charge recombination layers) in both thermal evaporated and solution processed organic tandem solar cell devices

Intermediate Layers in Tandem Organic Solar Cells

Tandem structures can boost the efficiency of organic solar cell to more than 15%, compared to the 10% limit of single layer bulk heterojunction devices. Design and fabricating of intermediate layers plays a very important role to achieve high device performance. This article will review the main experimental progresses of tandem organic solar cells, and focus on the intermediate layers (charge recombination layers) in both thermal evaporated and solution processed organic tandem solar cell devices

Tax-induced earnings management, auditor conservatism, and tax enforcement

Prompted by the recent statutory corporate income tax-rate reduction in China, in this study I investigate whether the constraining effect that quality auditors have on tax-related discretionary current accruals (DCA) differs for two sub-groups of listed firms with tax incentives to manage earnings upward versus downward. I also explore whether the effectiveness of tax authority scrutiny (i.e. tax enforcement) on DCA differs for the same two groups. I find that the firms’ two external monitors are sensitive to the direction of managerial incentives for earnings management. Specifically, higher-quality auditors are associated with smaller amounts of reported DCA and this association is stronger for firms with incentives to manage earnings upward and weaker for those with incentives to manage earnings downward, although the accrual decisions for all of the firms are driven by the same tax reporting incentives. The results are consistent with the notion that due to concerns with legal liability and reputation loss, auditors have incentives to ensure that firms report earnings conservatively. I also find a significantly positive association between tax enforcement and reported DCA for firms with incentives to manage earnings downward. This suggests that tax authorities constrain corporate accruals management that is likely to result in tax revenue loss. Taken together, my results suggest that a spillover effect exists between auditors and tax authorities, such that the two monitoring bodies compensate for each other’s lack of monitoring in one direction of accruals management. My results are robust to a set of sensitivity tests and have implications for academic researchers, policy makers, and capital market investors

Data-driven Topology Optimization of Channel Flow Problems

Typical topology optimization methods require complex iterative calculations, which cannot be realized in meeting the requirements of fast computing applications. The neural network is studied to reduce the time of computing the optimization result, however, the data-driven method for fluid topology optimization is less of discussion. This paper intends to introduce a neural network architecture that avoids time-consuming iterative processes and has a strong generalization ability for topology optimization for Stokes flow. Different neural network methods that have been already successfully used in solid structure optimization problems are mutated and examined for fluid topology optimization cases, including Convolution Neural Networks (CNN), conditional Generative Adversarial Networks (cGAN), and Denoising Diffusion Implicit Models (DDIM). The presented neural network method is tested on the channel flow topology optimization problems for Stokes flow. The results have shown that our presented method has high pixel accuracy, and we gain a 663 times decrease in execution time compared with the conventional method on average