Optical <i>in situ</i> monitoring of hydrogen desorption from Ge(100) surfaces

Barrigón, Enrique; Brückner, Sebastian; Supplie, Oliver; Kleinschmidt, Peter; Rey‐Stolle, Ignacio; Hannappel, Thomas

doi:10.1063/1.4798248

Cited by 7 publications

(13 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Temperature-dependent measurements showed sensitivities of 10 17 /cm 3 at 400 C to 1 Â 10 18 /cm 3 at 600 C [42]. Recent work has also shown that RAS can be used to monitor the hydrogen termination of Ge during annealing in N 2 (Figure 29.19) [45]. Recent work by Bruckner et al [44] showed that key details associated with As adsorption and termination of Ge, such as dimer orientation, as well as the surface step structure can be differentiated using RAS by careful experiments and complementary STM, XPS, and low-energy electron diffraction (LEED) characterization, as shown in Figure 29.18.…”

Section: Reflectance Anisotropy Spectroscopymentioning

confidence: 96%

In Situ Characterization of Epitaxy

Brown

Losurdo

2015

Handbook of Crystal Growth

View full text Add to dashboard Cite

Section: Reflectance Anisotropy Spectroscopymentioning

confidence: 96%

In Situ Characterization of Epitaxy

Brown

Losurdo

2015

Handbook of Crystal Growth

View full text Add to dashboard Cite

“…While there have been many RAS studies of Si(001) surfaces, there have been very few studies of Ge(001), with recent work focusing on in situ MOVPE studies, where RAS has unique advantages. [8][9][10][11] Regarding calculations of the spectral response, the situation is similar. Recently, we have calculated the optical response of some Si(001) and Ge(001) surfaces using a local-orbital-based hybrid density functional theory (DFT) approach.…”

mentioning

confidence: 89%

“…12 The experimental optical spectra from different studies are very similar, all having a minimum in the range of 1.8-2.0 eV, another minimum at 3.0 eV, and maxima around 2.2 and 4.2 eV, the E1 and E2 critical points of bulk Ge. 9,10 The calculated optical response for the c(4 Â 2) and p(2 Â 2) structures, using the hybrid DFT approach, is compared with the experiment in Fig. 2, where it can be seen that the spectral lineshape is well reproduced, although the reduced intensity of the $2 eV peak observed results in an almost entirely negative-going experimental spectrum.…”

mentioning

confidence: 99%

“…12 The LEED patterns obtained showed the vicinal surface spot splitting expected and, for the [111] offcut, a (1 Â 2)/(2 Â 1) pattern, with no dominant domain, while the [110] offcut was predominantly single domain, in agreement with previous work. [8][9][10] Antimony was evaporated onto the sample using a low temperature effusion cell. After deposition, the sample was annealed for 15 min at 680 K to remove excess Sb and form the (2 Â 1)-Sb structure.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Group V adsorbate structures on vicinal Ge(001) surfaces determined from the optical spectrum

Banerjee

Patterson

McGilp

2017

Applied Physics Letters

View full text Add to dashboard Cite

Vicinal Ge(001) is the standard substrate for the fabrication of high-performance solar cells by metal-organic vapour phase epitaxy, where growth of the III-V material on single domain Ge surfaces, with a single dimer orientation, minimizes the formation of anti-phase domain defects. Reflectance anisotropy spectroscopy has proved to be a powerful and sensitive optical probe of such anisotropic surface structures, but moving beyond fingerprinting to atomic structure determination from the optical spectra has been held back by the high computational cost. It is shown that an empirical, local-orbital-based hybrid density functional theory approach produces very good agreement between the theory and the experiment for (2 × 1)-As and (2 × 1)-Sb structures grown on vicinal Ge(001). These results, when taken together with previous work on Si interfaces, show that this computationally efficient approach is likely to prove to be an important general technique for determining the structure of anisotropic semiconductor surfaces and interfaces by comparing the experimental and calculated optical spectrum.

show abstract

“…Figure ) . This enabled in situ studies on the preparation of clean and monohydride terminated Ge(100) surfaces and the H desorption kinetics in MOVPE ambient, respectively . From DFT calculations and comparison to experimental results, however, the microscopic origin of the RA spectra could not yet be clarified due to lack of low temperature RAS data.…”

Section: Epitaxial Reference Surfacesmentioning

confidence: 99%

In Situ Characterization of Interfaces Relevant for Efficient Photoinduced Reactions

Supplie

May

Brückner

et al. 2017

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

which he pioneered and established. In general, interfaces do not only determine electronic properties of the final device; their atomic order also highly affects growth kinetics and defect formation. Moreover, the design of solid-liquid and hybrid interfaces determines their chemical reactivity and stability. In situ monitoring of interface preparation, formation, and interfacial reactions thus promises efficient process control. Paired with a detailed understanding of interface formation mechanisms, however, the true power of in situ control is to allow for specific modification and tuning of interface formation for the device of choice. There are several excellent reviews on in situ approaches covering wide ranges of materials from basic science to applications as well as varieties of preparation and analysis techniques. [2][3][4][5][6][7][8][9][10][11] As indicated in Figure 1, this review will be focused on in situ control over interfaces of materials that are relevant for photoinduced reactions in high-efficiency solar energy conversion and sensing applications with in situ control of semiconductor/polymer/ biological interfaces. We will restrict the techniques to realistic and complex, non-ultrahigh-vacuum (UHV) ambient, where in situ control is most demandingbut also highly desired. The more complex the interfacial reactions are, the more important is the in situ characterization. Ex situ approaches can contribute to an indirect understanding of interface formation, but to understand and, finally, control the dynamic processes taking place, real-time measurements are appropriate. The challenge, we are facing, is twofold: On the one hand, increased interaction with the surrounding ambient causes higher complexity. Yet at the same time, it decreases the number of applicable techniques. On the other hand, those techniques are often elaborate and not necessarily easy to interpret. In a nutshell, we will discuss four main topics:(i) Surface preparation during growth of structures for highefficiency solar energy conversion: World-record conversion efficiencies in both photovoltaics [12,13] and solar water splitting [14] are achieved with multijunction solar cells based on epitaxial III/V compound semiconductor structures. We will discuss in situ controlled preparation Solar energy conversion and photoinduced bioactive sensors are representing topical scientific fields, where interfaces play a decisive role for efficient applications. The key to specifically tune these interfaces is a precise knowledge of interfacial structures and their formation on the microscopic, preferably atomic scale. Gaining thorough insight into interfacial reactions, however, is particularly challenging in relevant complex chemical environment. This review introduces a spectrum of material systems with corresponding interfaces significant for efficient applications in energy conversion and sensor technologies. It highlights appropriate analysis techniques capable of monitoring critical physicochemical reactions in situ during non-vacuu...

show abstract

Optical in situ monitoring of hydrogen desorption from Ge(100) surfaces

Cited by 7 publications

References 36 publications

In Situ Characterization of Epitaxy

In Situ Characterization of Epitaxy

Group V adsorbate structures on vicinal Ge(001) surfaces determined from the optical spectrum

In Situ Characterization of Interfaces Relevant for Efficient Photoinduced Reactions

Contact Info

Product

Resources

About