Ni$_x$InSe (0001) Metal–Semiconductor Heteronanosystem Study

Abstract

Scanning tunnelling microscopy/spectroscopy (STM/STS) data show that InSe layered crystal intercalated with nickel is a heteronanosystem-InSe layerpacket that alternates with nickel at fine dispersed phase in the interlayer gap. For analysis of the degree of metallicity of cleavage surfaces, an array of STS data obtained in the current imaging tunnelling spectroscopy (CITS) mode is used. By significantly different behaviour of current-voltage curves for metal and semiconductor at localized points of surface analysis on the cleavage within the bias voltages that correspond to the band gap of the semiconductor, the method for the calculation of the relative metal concentration on the cleavage surface is proposed. The constraints for this method of the relative concentration estimates are analysed. As determined, the value of the nickel relative concentration in the interlayer gap for the Ni x InSe systems can be up to 2%, taking into account features of obtaining of the cleavage surfaces in the layered crystals. To establish the structural characteris- tics of the nickel, the STM analysis with high spatial resolution is used followed by the 2D FFT filtration and height profiling of image data. The analysis of corresponding revealed periodicities allows revealing formation of the two-dimensional square lattice of nickel on certain nanoscale areas of surface.Key words: scanning tunnelling microscopy and spectroscopy, current imaging tunnelling spectroscopy, local density of states, layered crystals, metal intercalation, heteronanostructures.Зà äîïîìîгîþ ìåтîä сêàíóâàëüíîї тóíåëüíîї ìіêðîсêîïії тà сïåêтðîсêîïії (СТÌ/СТС) âстàíîâëåíî, щî øàðóâàтèé êðèстàë InSe, іíтåðêàëüîâàíèé íі-êëåì, ïðåäстàâëÿє сîбîþ гåтåðîíàíîсèстåìó -øàð-ïàêåт InSe, ÿêèé ÷åð-гóєтüсÿ ç íіêëåì, щî çíàхîäèтüсÿ ó äðібíîäèсïåðсíіé ôàçі ó ìіжøàðîâіé щіëèíі. Дëÿ àíàëіçè стóïåíÿ «ìåтàëі÷íîстè» ïîâåðхíі сêîëåííÿ âèêîðèс-тàíî ìàсèâ äàíèх СТС, îäåðжàíèх ó ðåжèìі CITS (current imaging tunnelling spectroscopy). Зà істîтíî ðіçíîþ ïîâåäіíêîþ âîëüт-àìïåðíèх êðèâèх äëÿ ìåтàëó тà íàïіâïðîâіäíèêà â ëîêàëüíèх тî÷êàх àíàëіçè íà ïîâåðхíі âіäêîëó, îäåðжàíèх ó äіÿïàçîíі íàïðóг çìіщåííÿ, ÿêі âіäïîâіäàþтü çàбî-ðîíåíіé çîíі íàïіâïðîâіäíèêà, çàïðîïîíîâàíî ìåтîäó îбðàхóíêó âіäíîс-íèх êîíöåíтðàöіé ìåтàëó íà ïîâåðхíі сêîëåííÿ. Пðîàíàëіçîâàíî îбìå-жåííÿ тàêîї ìåтîäè îöіíþâàííÿ âіäíîсíèх êîíöåíтðàöіé. Âстàíîâëåíî, щî âåëè÷èíà âіäíîсíîї êîíöåíтðàöії íіêëþ ó ìіжøàðîâіé щіëèíі äëÿ сèс-тåì Ni x InSe ìîжå äîсÿгàтè бëèçüêî 2%, âðàхîâóþ÷è îсîбëèâîсті îäåð-жàííÿ ïîâåðхîíü сêîëåííÿ äëÿ øàðóâàтîгî êðèстàëó. Дëÿ âстàíîâëåííÿ стðóêтóðíèх хàðàêтåðèстèê íіêëþ âèêîðèстàíî СТÌ-àíàëіçó ç âèсîêîþ ïðîстîðîâîþ ðîçäіëü÷îþ çäàтíістþ ç íàстóïíîþ 2D-FFT-ôіëüтðàöієþ і âè-сîтíèì ïðîôіëþâàííÿì îäåðжàíèх çîбðàжåíü. Àíàëіçà âіäïîâіäíèх ïåðі-îäè÷íîстåé óìîжëèâèëà âèÿâèтè ôîðìóâàííÿ äâîâèìіðíîї êâàäðàтíîї ґðàтíèöі íіêëþ íà îêðåìèх íàíîìàсøтàбíèх äіëÿíêàх ïîâåðхíі.Ключові слова: сêàíóâàëüíà тóíåëüíà ìіêðîсêîïіÿ, сêàíóâàëüíà тóíåëü-íà сïåêтðîсêîïіÿ, ëîêàëüíà гóстèíà стàíіâ, øàðóâàтèé êðèстàë, іíтåðêà-ëÿöіÿ ìåтà...

Indium Deposited Nanosystem Formation on InSe (0001) Surface Applied as Template

“…Particularly, 2D layered semiconductor InSe is the object of modern research suitable for the functional nanoscale devices applications [2], for example, in the future super-fast electronics [3]. We previously reported on the valuable nanoscale properties of Ni õ InSe hybrid metal-semiconductor system obtained as self-assembling system due to intercalation process [4]. A number of studies concerning the application of In 4 Se 3 crystal were presented, such as In 4 Se 3 based field effect transistor [5], thermoelectricity generation [6].…”