过渡金属硫族化合物(transition metal dichalcogenides,TMDs)因其显著的光学和电学特性而受到广泛的关注。其块状材料为间接带隙半导体,而单层材料则具有直接带隙半导体的特性。对于单层半导体材料,其拥有原子级别的厚度,容易引入外界...过渡金属硫族化合物(transition metal dichalcogenides,TMDs)因其显著的光学和电学特性而受到广泛的关注。其块状材料为间接带隙半导体,而单层材料则具有直接带隙半导体的特性。对于单层半导体材料,其拥有原子级别的厚度,容易引入外界环境掺杂,从而影响其发光特性。本文通过化学气相沉积法合成高质量,大面积的单层及少数层N-型二硫化钨(WS_(2))材料。使用拉曼进行表征,通过其特征声子振动模式所对应的频率差,来确定材料层数。在此基础上,对比了材料中心和边缘的光致发光(Photoluminescence,PL)。相比于中心位置,边缘位置的荧光强度更强,且峰位也发生红移。这是由于生长过程中造成的缺陷密度不同。基于此,使用掺杂剂对材料进行处理,来改变其缺陷密度。处理后发现,边缘和中心位置峰位均发生蓝移,强度减弱,同时中性激子发射占据了主导。该结果也进一步证实了本文生长的单层WS_(2)为N-型半导体材料。展开更多
Paper-based devices have attracted extensive attention due to the growing demand for disposable flexible electronics.Herein,we integrate semiconducting devices on cellulose paper substrate through a simple abrasion te...Paper-based devices have attracted extensive attention due to the growing demand for disposable flexible electronics.Herein,we integrate semiconducting devices on cellulose paper substrate through a simple abrasion technique that yields high-performance photodetectors.A solvent-free WS_(2) film deposited on paper favors an effective electron-hole separation and hampers recombination.The as-prepared paper-based WS2 photodetectors exhibit a sensitive photoresponse over a wide spectral range spanning from ultraviolet(365 nm)to near-infrared(940 nm).Their responsivity value reaches up to~270 mA W^(−1) at 35 V under a power density of 35 mW cm^(−2).A high performance photodetector was achieved by controlling the environmental exposure as the ambient oxygen molecules were found to decrease the photoresponse and stability of the WS_(2) photodetector.Furthermore,we have built a spectrometer using such a paperbased WS_(2) device as the photodetecting component to illustrate its potential application.The present work could promote the development of cost-effective disposable photodetection devices.展开更多
文摘过渡金属硫族化合物(transition metal dichalcogenides,TMDs)因其显著的光学和电学特性而受到广泛的关注。其块状材料为间接带隙半导体,而单层材料则具有直接带隙半导体的特性。对于单层半导体材料,其拥有原子级别的厚度,容易引入外界环境掺杂,从而影响其发光特性。本文通过化学气相沉积法合成高质量,大面积的单层及少数层N-型二硫化钨(WS_(2))材料。使用拉曼进行表征,通过其特征声子振动模式所对应的频率差,来确定材料层数。在此基础上,对比了材料中心和边缘的光致发光(Photoluminescence,PL)。相比于中心位置,边缘位置的荧光强度更强,且峰位也发生红移。这是由于生长过程中造成的缺陷密度不同。基于此,使用掺杂剂对材料进行处理,来改变其缺陷密度。处理后发现,边缘和中心位置峰位均发生蓝移,强度减弱,同时中性激子发射占据了主导。该结果也进一步证实了本文生长的单层WS_(2)为N-型半导体材料。
基金Felix Carrascoso (ICMM-CSIC) for support with the metal evaporationfunding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement n°755655,ERC-StG 2017 project2D-TOPSENSE)+5 种基金the Ministry of Science and Innovation (Spain) through the project PID2020-115566RB-I00support from the National Natural Science Foundation of China under grant No.61704129 and No.62011530438the Key Research and Development Program of Shaanxi (Program No.2021KW-02)Fundamental Research Funds for the Central Universities (JB211409)the grant from China Scholarship Council (CSC) under No.201908610178the support from European Union’s Horizon 2020 research and innovation program under the grant agreement 956813 (2Exciting)。
文摘Paper-based devices have attracted extensive attention due to the growing demand for disposable flexible electronics.Herein,we integrate semiconducting devices on cellulose paper substrate through a simple abrasion technique that yields high-performance photodetectors.A solvent-free WS_(2) film deposited on paper favors an effective electron-hole separation and hampers recombination.The as-prepared paper-based WS2 photodetectors exhibit a sensitive photoresponse over a wide spectral range spanning from ultraviolet(365 nm)to near-infrared(940 nm).Their responsivity value reaches up to~270 mA W^(−1) at 35 V under a power density of 35 mW cm^(−2).A high performance photodetector was achieved by controlling the environmental exposure as the ambient oxygen molecules were found to decrease the photoresponse and stability of the WS_(2) photodetector.Furthermore,we have built a spectrometer using such a paperbased WS_(2) device as the photodetecting component to illustrate its potential application.The present work could promote the development of cost-effective disposable photodetection devices.
