Halide perovskite solar cells (PSCs) are considered as one of the most promising candidates for the next generation solar cells as their power conversion efficiency (PCE) has rapidly increased up to 25.2%. However, the most efficient halide perovskite materials all contain toxic lead. Replacing the lead cation with environmentally friendly tin (Sn) is proposed as an important alternative. Today, the inferior performance of Sn-based PSCs mainly due to two challenging issues, namely the facile oxidation of Sn2+ to Sn4+ and the low formation energies of Sn vacancies. Two-dimensional (2D) halide perovskite, in which the large sized organic cations confine the corner sharing BX6 octahedra, exhibits higher formation energy than that of three-dimensional (3D) structure halide perovskite. The approach of mixing a small amount of 2D into 3D Sn-based perovskites was demonstrated as an efficient method to produce high performance perovskite films. In this review, we first provide an overview of key points for making high performance PSCs. Then we give an introduction to the physical parameters of 3D ASnX3 (MA+, FA+, and Cs+) perovskite and a photovoltaic device based on them, followed by an overview of 2D/3D halide perovskites based on ASnX3 (MA+ and FA+) and their optoelectronic applications. The current challenges and a future outlook of Sn-based PSCs are discussed in the end. This review will give readers a better understanding of the 2D/3D Sn-based PSCs.

In order to compensate the threshold voltage variation while obtaining the sufficient data charging time, the AMOLED compensative pixel circuit needs to be driven by multi-pulse signals which have continuous high/low level pulses. By using traditional gate driver on array (GOA) with half duty-cycle delay of clock signals, the area of shift register is doubled, increasing the bezel width and power consumptions. In this paper, novel compact integrated gate driver circuit architectures for AMOLED pixel compensation purpose are presented. Outputs with programmable pulse width and number are achieved in these gate driving circuits without consuming extra large areas. Inner feedback technique is adopted in GOA circuit for leakage current cutting of depletion mode IGZO TFTs. The simulation result shows that these circuits work successfully with maximum ±3V threshold voltage shift. These GOA circuits can be used for internal or external Vth compensation techniques of AMOLED panel.

A novel gate driver on array (GOA) circuit topology based on pulse width modulation (PWM) technique has been proposed for internal compensation AMOLED pixel driving. The output width of PWM GOA basic unit can be easily adjusted by tuning start pulse (STU) signal width. The performance of this circuit has been verified by simulation and the prototype has been fabricated in 5 inch AMOLED panel with IGZO TFT process. There are three main features of PWM GOA circuit, (1) PWM GOA is properly designed with depletion mode IGZO TFTs (2) Output pulse width can be easily changed by tuning STU's width without additional circuits (3) Interface and accessory of PWM GOA is custom designed to realize different function of each block. ThisGOA structure provides a practical way to realize narrow bezel design.

All-inorganic halide perovskites are emerging as a class of superstar semiconductors with excellent optoelectronic properties and show great potential for a broad range of applications in solar cells, lighting diodes, X-ray imaging, and photodetectors. Tremendous research about their device performance has been performed since 2015. In this study, we synthesized the all-inorganic perovskite by the hot-injection method and particularly investigated their crystal structural and photoluminescence properties. By halide anion engineering, the all-inorganic perovskites showed a high-symmetry cubic phase. They also showed a tunable optical bandgap, and almost the full color luminescence was achieved (434 to 624 nm). These basic optoelectronic properties could give a guide for further development of this area.

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