Pei Junxiang, Wu Xiaohan, Huo Jingyong, Liu Wen-Jun, Zhang David Wei, Ding Shi-Jin
State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, People's Republic of China.
Nanotechnology. 2021 Feb 26;32(9):095204. doi: 10.1088/1361-6528/abc6e0.
The electronic-photonic convergent systems can overcome the data transmission bottleneck for microchips by enabling processor and memory chips with high-bandwidth optical input/output. However, current silicon-based electronic-photonic systems require various functional devices/components to convert high-bandwidth optical signals into electrical ones, thus making further integrations of sophisticated systems rather difficult. Here, we demonstrate thin-film transistor-based photoelectric memories employing CsPbBr/CsPbI blend perovskite quantum dots (PQDs) as a floating gate, and multilevel memory cells are achieved under programming and erasing modes, respectively, by imputing high-bandwidth optical signals. For different bandwidth light input (i.e. 500-550, 575-650 and 675-750 nm) with the same intensity, three levels of programming window (i.e. 3.7, 1.9 and 0.8 V) and erasing window (i.e. -1.9, -0.6 and -0.1 V) are obtained under electrical pulses, respectively. This is because the blend PQDs have two different bandgaps, and different amounts of photo-generated carriers can be produced for different wavelength optical inputs. It is noticed that the 675-750 nm light inputs have no effects on both programming and erasing windows because of no photo-carriers generation. Four memory states are demonstrated, showing enough large gaps (1.12-5.61 V) between each other, good data retention and programming/erasing endurance. By inputting different optical signals, different memory states can be switched easily. Therefore, this work directly demonstrates high-bandwidth light inputting multilevel memory cells for novel electronic-photonic systems.
电子 - 光子收敛系统可以通过为处理器和存储芯片提供高带宽光输入/输出，克服微芯片的数据传输瓶颈。然而，目前基于硅的电子 - 光子系统需要各种功能器件/组件将高带宽光信号转换为电信号，这使得复杂系统的进一步集成变得相当困难。在此，我们展示了基于薄膜晶体管的光电存储器，其采用CsPbBr/CsPbI混合钙钛矿量子点（PQDs）作为浮栅，通过输入高带宽光信号，分别在编程和擦除模式下实现了多级存储单元。对于相同强度的不同带宽光输入（即500 - 550、575 - 650和675 - 750 nm），在电脉冲下分别获得了三个编程窗口电平（即3.7、1.9和0.8 V）和擦除窗口电平（即 -1.9、-0.6和 -0.1 V）。这是因为混合PQDs具有两个不同的带隙，并且对于不同波长的光输入可以产生不同数量的光生载流子。值得注意的是，675 - 750 nm的光输入对编程和擦除窗口均无影响，因为没有光生载流子产生。展示了四种存储状态，它们之间具有足够大的间隙（1.12 - 5.61 V）、良好的数据保持能力和编程/擦除耐久性。通过输入不同的光信号，可以轻松切换不同的存储状态。因此，这项工作直接展示了用于新型电子 - 光子系统的高带宽光输入多级存储单元。
