Multiparameter Statistical Design of Experiments for GaN Growth Optimization

Bar-Ilan, Amnon; Zamir, S.; KatzBar-Ilan, O.; Meyler, B.; Salzman, J.

doi:10.1002/(sici)1521-396x(199911)176:1<313::aid-pssa313>3.0.co;2-5

Cited by 6 publications

(2 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The influence of various parameters on the band gap position of colloidal CdS nanoparticles has been widely investigated. − In most of these studies the classical experimental design was used whereby one parameter is systematically varied while the others are kept constant, thus disregarding possible parameter interactions. In this paper the Statistical Design of Experiments (DoE) − is used to explore the influence of three synthesis parameters on the band gap energies of CdS nanoparticles, namely, the concentration of the stabilizers cysteine and glutathione, respectively, the concentration of the sulfidation reagent, and the pH value of the sols. We have chosen not to perform exchange of the capping ligands of CdS nanoparticles as described in the literature − because of the potentially incomplete exchange of the quantum dot surface , and because of the facile preparation of the biostabilized nanoparticles comprising a one-pot-process and mild synthesis conditions such as room temperature and the use of water as solvent.…”

Section: Introductionmentioning

confidence: 99%

Adjustment of the Band Gap Energies of Biostabilized CdS Nanoparticles by Application of Statistical Design of Experiments

et al. 2004

View full text Add to dashboard Cite

The colloidal synthesis of CdS nanoparticles with the biostabilizers cysteine and glutathione, respectively, at pH values ranging from 4 to 10 is described. For the adjustment of their UV/Vis absorption properties and hence their band gap energies, the Statistical Design of Experiments (DoE) was used. This method allows the simultaneous variation of the synthesis parameters in a systematic manner, and thereby synergistic interaction effects can be obtained. The band gap energies of the quantum dots can be tuned from 3.32 to 4.26 eV by varying kind and concentration of stabilizer, pH value, and concentration of sulfide source. The energy position is significantly dependent on the interaction between the pH value and the concentration of the stabilizer, and the effect of high glutathione concentration is opposite at acidic and alkaline conditions thus leading to band gaps of 4.10 eV at pH = 6 and of 3.64 eV at pH = 10. Examples for the synthesis of semiconductor nanoparticles with predefined spectroscopic properties and preset preparation conditions, e.g., alkaline conditions for the implementation of acid-sensitive dopants, are given.

show abstract

Section: Introductionmentioning

confidence: 99%

Adjustment of the Band Gap Energies of Biostabilized CdS Nanoparticles by Application of Statistical Design of Experiments

et al. 2004

View full text Add to dashboard Cite

show abstract

“…A thin AlGaN barrier layer was introduced 1000 Å above the buffer layer to prevent perturbation in the electrical measurements by the shunt conductance at the layer-buffer interface. 21 The main GaN layer thickness over the 2 in. sample was 800Ϯ10 nm.…”

mentioning

confidence: 99%

Thermally activated electrical conductivity in thin GaN epitaxial films

Salzman

Uzan‐Saguy

Kalish

et al. 2000

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

show abstract

Vertical versus Lateral GaN Schottky Ultraviolet Detectors and Their Gain Mechanism

Katz

Garber

Meyler

et al. 2001

phys. stat. sol. (a)

Self Cite

View full text Add to dashboard Cite

We have implemented Schottky barrier GaN ultraviolet detectors, both in vertical and in lateral configuration. The devices exhibit a high gain at both reverse and forward bias. The gain mechanism is attributed to trapping of minority carriers at the semiconductor-metal interface, with excellent agreement between the calculated responsivity and the experiment. However, the vertical detector zero-bias responsivity (without gain) is two orders of magnitude higher. This is attributed to improved ohmic back contacts, due to the highly doped buried layer.Schottky barrier ultraviolet (UV) detectors have been an attractive photovoltaic structure, providing high response, low noise, fast response time and easy fabrication. Ideal photovoltaic devices are not expected to exhibit gain. One of the issues yet unexplained in GaN based Schottky UV detectors, has been the presence of gain [1,2]. Presently, the III-nitride films are grown hetero-epitaxially on mismatched substrates [3]. This results in a rich microstructure dominated by dislocations that traverse vertically from the layer-substrate interface, all the way up to the film surface [4]. Typical dislocation density in GaN epitaxial layers is 10 8 -10 11 cm --2 [5]. We have recently demonstrated that the preferential orientation of the dislocations manifests itself in an intrinsic anisotropy in transport properties of the film [6]. Although lateral and vertical geometry GaN-based Schottky detectors have been already fabricated [1,2], no comparison has been made between the two detector configurations.In this work we explain the gain mechanism in GaN based Schottky detectors, and its bias dependence, for both detector structure types. We show that the vertical detector exhibits higher responsivity, lower 1/f noise, resulting in better detection properties.The layers used were grown by low-pressure metal organic chemical vapor deposition (MOCVD). For details see Ref.[7]. The vertical Schottky barrier detector (Fig. 1b) was fabricated by defining %300 mm diameter circular mesas. On the n + -GaN layer around the mesas, ohmic contacts were evaporated, using Ti : Al : Ni : Au (15, 220, 40, and phys. stat

show abstract

Multiparameter Statistical Design of Experiments for GaN Growth Optimization

Cited by 6 publications

References 12 publications

Adjustment of the Band Gap Energies of Biostabilized CdS Nanoparticles by Application of Statistical Design of Experiments

Adjustment of the Band Gap Energies of Biostabilized CdS Nanoparticles by Application of Statistical Design of Experiments

Thermally activated electrical conductivity in thin GaN epitaxial films

Vertical versus Lateral GaN Schottky Ultraviolet Detectors and Their Gain Mechanism

Contact Info

Product

Resources

About