An oxide-based heterojunction optoelectronic synaptic device with wideband and rapid response performance

doi:10.1016/j.jmst.2021.11.082

Abstract

Abstract:

With the rapid development of science and technology, the emergence of new application scenarios, such as robots, driverless vehicles and smart city, puts forward high requirements for artificial visual systems. Optoelectronic synaptic devices have attracted much attention due to their advantages in sensing, memory and computing integration. In this work, via band structure engineering and heterostructure designing, a heterojunction optoelectronic synaptic device based on Cu doped with n-type SrTiO₃(Cu:STO) film combined with p-type CuAlO₂(CAO) thin film was fabricated. It is found surprisingly that the optoelectronic device based on Cu:STO/CAO p-n heterojunction exhibits a rapid response of 2 ms, and that it has a wideband response from visible to near-infrared (NIR) region. Additionally, a series of important synaptic functions, including excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), short-term potentiation (STP) to long-term potentiation (LTP) transition, learning experience behavior and image sharpening, have been successfully simulated on the device. More importantly, the performance of the device remains still stable and reliable after several months which were stored at room temperature and atmospheric pressure. Based on these advantages, the optoelectronic synaptic devices demonstrated here provide great potential in the new generation of artificial visual systems.

Key words: Cu:STO/CAO heterojunction, Optoelectronic synaptic devices, Vis to NIR wideband, Rapid response, Artificial visual system

Chunmei Li, Jinyong Wang, Dongyang Li, Nasir Ilyas, Zhiqiang Yang, Kexin Chen, Peng Gu, Xiangdong Jiang, Deen Gu, Fucai Liu, Yadong Jiang, Wei Li. An oxide-based heterojunction optoelectronic synaptic device with wideband and rapid response performance[J]. J. Mater. Sci. Technol., 2022, 123: 159-167.

Figures/Tables 5

Fig. 1. The structure and characteristics of the ITO/Cu:STO/CAO/ITO synaptic device. (A) Structural diagram of the device. (B) Cross-sectional TEM image of the Cu:STO and CAO layers on the ITO substrate. (C) UV-Vis-NIR absorbance spectrum of the Cu:STO film with the curve of hν versus (Ahν)2 (inset). (D) Cu 2p, (E) Sr 3d, (F) Ti 2p and (G) O 1s are the separate XPS spectra of the Cu:STO film, respectively.

Fig. 2. The EPSC characteristics of the ITO/Cu:STO/CAO/ITO synaptic device irradiated by a laser. The light wavelength is set at 520 nm, the power density at 20 mW/cm2, the angle between the device surface and the light beam at 45 degrees, and the bias voltage at 0.06 V, respectively. (A) Dependence of the EPSC on the duration of light on and off. (B) Typical PPF behavior of the synaptic device spiked by a light with a width of 3 s and interval of 200 ms. (C) The variation of PPF index and its fitting curve with light pulse interval time Δt. (D) The EPSC at 0.25 Hz, 0.1 Hz and 0.05 Hz during a stimulating of 60 s light pulse, the inset shows an enlarged drawing within 60 s. (E) Short-term potentiation (STP) to long-term potentiation (LTP) transition induced by increasing stimulating number of the light pulse with a period of 0.5 s and a duty cycle of 80%. (F) Learning experience behavior of the device.

Fig. 3. The optoelectronic performance of ITO/Cu:STO/CAO/ITO device. (A) Distribution of EPSC at diverse read voltage and power density irradiated by a light beam at 520 nm. (B) Changes of EPSC induced by different angles of light beam at 520 nm and 20 mW/cm2. (C) A rapid response of EPSC stimulated by a light beam within 2 ms at 520 nm and 65 mW/cm2. (D) Normalized EPSC obtained by a light excitation lasting for 2 s at different power density (20 mW/cm2-55 mW/cm2) and varied wavelength (520 nm-980 nm), respectively.

Fig. 4. The sharpening and memorizing functions simulating human vision by an array of 4 × 7 pixels of ITO/Cu:STO/CAO/ITO synaptic devices. Input image was encoded at light power density of 20 mW/cm2, period of 0.5 s and duty cycle of 80%, varied at different wavelengths with stimulating time of 0 s (A), 20 s (B) and forgetting for 40 s (C). Input image was encoded at light wavelength of 520 nm, period of 0.5 s and duty cycle of 80%, fixed irradiation angle of 45°, varied at different stimulating time of 0 s (D), 10 s (E) and forgetting for 40 s (F). Input image was encoded at light wavelength of 520 nm, power density of 20 mW/cm2, period of 0.5 s and duty cycle of 80%, varied at different irradiation angles with stimulating time of 0 s (G), 10 s (H) and forgetting for 40 s (I).

Table 1. Comparison of the ITO/Cu:STO/CAO/ITO Synaptic Device and Previously Reported Similar Optoelectronic Synaptic Devicesa

Devices	Wavelength range (nm)	Rapidest time (ms)	Angle modulation	PPF	Learning experience	Ref.
Al/TiN_xO_2-_x/MoS₂/ITO	365-940	50	no	yes	yes	[41]
Au/2D-ZnO/SiO₂/Si	280-365	500	no	yes	yes	[42]
Au/Graphene/MoS₂/Si/SiO₂	532	1	no	no	no	[43]
ITO/TiO₂-In₂O₃(N₂)/Au	470	no	no	yes	no	[44]
Pyr-GDY/Gr/PbS-QDs	450, 980	20	no	yes	no	[19]
ITO/Nb:SrTiO₃	459-630	no	no	yes	yes	[12]
ITO/Si-NC/Al	375-1870	100	no	yes	no	[20]
ITO/Cu:STO/CAO/ITO	520-1550	2	yes	yes	yes	This work

References 46

[1]	A.P.P. Kasznar, A.W.A. Hammad, M. Najjar, E.L. Qualharini, K. Figueiredo, C. A. Pereira Soares, A.N. Haddad, Buildings 11 (2021) 73. DOI URL
[2]	Y. Li, S. Tian, Y. Huang, W. Dong, Transl. Oncol. 14 (2021) 100896. DOI URL
[3]	S. Chen, Z. Lou, D. Chen, G. Shen, Adv. Mater. 30 (2018) 1705400. DOI URL
[4]	Y. Tang, M. Chen, C. Wang, L. Luo, J. Li, G. Lian, X. Zou, Front. Plant Sci. 11 (2020) 510. DOI URL
[5]	J. Yang, C. Wang, B. Jiang, H. Song, Q. Meng, IEEE Trans. Ind. Inform. 17 (2021) 2204-2219. DOI URL
[6]	Y.-R. Chen, K. Chao, M.S. Kim, Comput. Electron. Agric. 36 (2002) 173-191. DOI URL
[7]	R. Bogue, Ind. Robot Int. J. 40 (2013) 415-419. DOI URL
[8]	R. Vaquer-Sunyer, C.M. Duarte, L. Bopp, C.L. Quere, M. Heimann, A.C. Manning, P. Monfray, R.J. Matear, A.C. Hirst, Science 345 (2014) 668-673. DOI URL
[9]	K.H. Jeong, J. Kim, L.P. Lee, Science 312 (2006) 557-561. PMID
[10]	G. Indiveri, S. Liu, Proc, IEEE 103 (2015) 1379-1397. DOI URL
[11]	D. Li, C. Li, N. Ilyas, X. Jiang, F. Liu, D. Gu, M. Xu, Y. Jiang, W. Li, Adv. Intell. Syst. 2 (2020) 10.
[12]	S. Gao, G. Liu, H. Yang, C. Hu, Q. Chen, G. Gong, W. Xue, X. Yi, J. Shang, R.-W. Li, ACS Nano 13 (2019) 2634-2642. DOI URL
[13]	S. Seo, S.-H. Jo, S. Kim, J. Shim, S. Oh, J.-H. Kim, K. Heo, J.-W. Choi, C. Choi, S. Oh, D. Kuzum, H.-S.P. Wong, J.-H. Park, Nat. Commun. 9 (2018) 5106. DOI URL
[14]	M. Li, Z. Xiong, S. Shao, L. Shao, S.-T. Han, H. Wang, J. Zhao, Carbon 176 (2021) 592-601.
[15]	W. Huang, P. Hang, Y. Wang, K. Wang, S. Han, Z. Chen, W. Peng, Y. Zhu, M. Xu, Y. Zhang, Y. Fang, X. Yu, D. Yang, X. Pi, Nano Energy 73 (2020) 104790. DOI URL
[16]	Y. Chu, X. Wu, J. Lu, D. Liu, J. Du, G. Zhang, J. Huang, Adv. Sci. 3 (2016) 1500435. DOI URL
[17]	C. Ye, Q. Peng, M. Li, J. Luo, Z. Tang, J. Pei, J. Chen, Z. Shuai, L. Jiang, Y. Song, J. Am. Chem. Soc. 134 (2012) 20 053-20 059.
[18]	L. Shao, M. Li, P. Wu, F. Wang, S. Chen, W. Hu, H. Wang, Z. Cui, J. Zhao, J. Mater. Chem. C 8 (2020) 6914-6922. DOI URL
[19]	Y.-X. Hou, Y. Li, Z.-C. Zhang, J.-Q. Li, D.-H. Qi, X.-D. Chen, J.-J. Wang, B.-W. Yao, M.-X. Yu, T.-B. Lu, J. Zhang, ACS Nano 15 (2021) 1497-1508. DOI PMID
[20]	H. Tan, Z. Ni, W. Peng, S. Du, X. Liu, S. Zhao, W. Li, Z. Ye, M. Xu, Y. Xu, X. Pi, D. Yang, Nano Energy 52 (2018) 422-430. DOI URL
[21]	R. Merkle, J. Maier, Angew. Chem., Int. Ed. 47 (2008) 3874-3894. DOI URL
[22]	M. Rizwan, A. Ali, Z. Usman, N.R. Khalid, H.B. Jin, C.B. Cao. Phys. B Condens. Matter 552 (2019) 52-57.
[23]	H. Nili, S. Walia, S. Balendhran, D.B. Strukov, M. Bhaskaran, S. Sriram, Adv. Funct. Mater. 24 (2014) 6741-6750. DOI URL
[24]	M.A. Ferreira G.T.S.T. da Silva, O.F. Lopes, V.R. Mastelaro, C. Ribeiro. M.J.M. Pires, A.R. Malagutti, W. Avansi H.A.J.L. Mourão, Mater. Sci. Semicond. Process. 108 (2020) 104887. DOI URL
[25]	M. Kumar, P. Basera, S. Saini, S. Bhattacharya, Sci. Rep. 10 (2020) 15372. DOI URL
[26]	Y. Zheng, Z. Yu, H. Ou, A.M. Asiri, Y. Chen, X. Wang, Adv. Funct. Mater. 28 (2018) 1705407. DOI URL
[27]	H. Xu, M. Karbalaei Akbari, F. Verpoort, S. Zhuiykov, Nanoscale 12 (2020) 20177-20188. DOI URL
[28]	Y. Cheng, H. Li, B. Liu, L. Jiang, M. Liu, H. Huang, J. Yang, J. He, J. Jiang, Small 16 (2020) 2005217. DOI URL
[29]	M.E. Pilleux, C.R. Grahmann, V.M. Fuenzalida, R.E. Avila, Appl. Surf. Sci. 65-66 (1993) 283-288.
[30]	J.-Y. Baek, L.T. Duy, S.Y. Lee, H. Seo, J. Mater. Sci. Technol. 42 (2020) 28-37. DOI URL
[31]	S.B. Hofer, T. Bonhoeffer, Curr. Biol. 20 (2010) R157-R159. DOI URL
[32]	X. Wang, Y. Lu, J. Zhang, S. Zhang, T. Chen, Q. Ou, J. Huang, Small 17 (2021) 2005491. DOI URL
[33]	R.S. Zucker, W.G. Regehr, Annu. Rev. Physiol. 64 (2002) 355-405. DOI URL
[34]	W.G. Regehr, Cold Spring Harb. Perspect. Biol. 4 (2012) a005702.
[35]	L. Abbott, S. Nelson, Nat. Neurosci. 3 (2000) 1178-1183. DOI URL
[36]	J.L. McGaugh, Science 287 (2000) 248-251. PMID
[37]	M. Lee, W. Lee, S. Choi, J.-W. Jo, J. Kim, S.K. Park, Y.-H. Kim, Adv. Mater. 29 (2017) 1700951. DOI URL
[38]	G. Liu, C. Wang, W. Zhang, L. Pan, C. Zhang, X. Yang, F. Fan, Y. Chen, R.-W. Li, Adv. Electron. Mater. 2 (2016) 1500298. DOI URL
[39]	S.B. Hofer, T.D. Mrsic-Flogel, T. Bonhoeffer, M. Hübener, Nature 457 (2009) 313-317. DOI URL
[40]	M. Yang, J. Wang, Y. Zhao, L. He, C. Ji, X. Liu, H. Zhou, Z. Wu, X. Wang, Y. Jiang, ACS Nano 13 (2019) 755-763. DOI URL
[41]	W. Wang, S. Gao, Y. Li, W. Yue, H. Kan, C. Zhang, Z. Lou, L. Wang, G. Shen, Adv. Funct. Mater. 2101201 (2021) 1-10.
[42]	V. Krishnamurthi, T. Ahmed, M. Mohiuddin, A. Zavabeti, N. Pillai, C.F. Mc-Conville, N. Mahmood, S. Walia, Adv. Opt. Mater. 2100449 (2021) 6-14.
[43]	J. Yu, X. Yang, G. Gao, Y. Xiong, Y. Wang, J. Han, Y. Chen, H. Zhang, Q. Sun, Z. L. Wang, Sci. Adv. 7 (2021) eabd9117. DOI URL
[44]	M.K. Akbari, R.K. Ramachandran, C. Detavernier, J. Hu, J. Kim, F. Verpoort, S. Zhuiykov, J. Mater. Chem. C 9 (2021) 2539-2549. DOI URL
[45]	L. Zhang, H.Y. Xu, Z.Q. Wang, H. Yu, X.N. Zhao, J.G. Ma, Y.C. Liu, Appl. Phys. Lett. 104 (2014) 093512. DOI URL
[46]	J.J. Yu, L.Y. Liang, L.X. Hu, H.X. Duan, W.H. Wu, H.L. Zhang, J.H. Gao, F. Zhuge, T. C. Chang, H.T. Cao, Nano Energy 62 (2019) 772-780. DOI