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We present 6-inch n-type Cz-Si metal wrap through (MWT) solar cells with screen-printed and fired contacts achieving energy conversion efficiencies up to 20.4%. These so-called n-type high-performance MWT (n-HIP-MWT) structures feature different rear side configurations at the external p-type contacts with respect to the phosphorus-doped back surface field (BSF). It is shown that the alteration of the phosphorus dopant concentration at the silicon surface below the external rear p-type contacts allows for both decreasing reverse-bias-induced losses and adjusting the current flowing in reverse mode.

The growth of well-defined regular columnar macropores under front-side illumination on medium doped n-type silicon has been investigated. The various morphologies observed, with branched or columnar pores, differ from those reported so far on substrates of both higher and lower resistivities. Unlike stated by the macropore growth model, current density is found to influence the pore growth rate. These observations indicate that, under the conditions used in this work, the pore growth is at the border between meso- and macroporous mechanism. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Dynamic nuclear polarization of the 29Si nuclei due to the “solid-effect” was observed clearly after saturation of the phosphorus electron paramagnetic resonance lines in three kinds of silicon crystals containing different amount of the 29Si isotope (1%, 4.7%, and 99.3%). Maximal enhancement (E) of the room-temperature 29Si nuclear magnetic resonance signals E ≈ 605 was obtained at the temperatures of 10–14 K in silicon containing 1% of the 29Si isotope. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We measure very high minority-carrier lifetimes exceeding 20 ms on 1.4-Ω cm n-type Czochralski silicon wafers passivated using plasma-assisted atomic-layer-deposited Al2O3 on both wafer surfaces. The measured maximum effective lifetimes are surprisingly high as they significantly exceed the intrinsic lifetime limit previously reported in the literature. We are able to measure such high lifetimes by realizing an exceptionally homogeneous Al2O3 surface passivation on large-area samples (12.5 × 12.5 cm2). The importance of the homogeneous passivation is demonstrated by comparison with samples of locally reduced passivation quality.

Using specially “designed” electrolytes, it is possible to obtain macropores even in highly doped n-type silicon (0.020–0.060 Ωcm) without illumination. Based on predictions of the “current-burst-model” [phys. stat. sol. (a) 182, 63 (2000), this issue], HF-containing electrolytes were systematically modified with strongly oxidizing components and evaluated with respect to their ability to produce macropores. Well developed macropores with depths up to 10 μm and pore diameters between 200 nm and 2 μm could be obtained in several cases. The macropore nucleation starts with a facetting of the surface on {111} planes.

The crystal orientation dependence of macropore formation in n-type Si using aqueous electrolytes provided important information on pore formation mechanisms. Since macropores can also be obtained in organic electrolytes (especially for p-type Si), the orientation dependence for these electrolytes is of interest and therefore was studied. The observed pore morphologies are often remarkably different from the ones observed in aqueous electrolytes under comparable conditions. The results can be understood in terms of the current burst model, Carstensen et al., Mater. Sci. Eng. B 69/70, 23 (2000).

Iridium-related deep levels in n-type silicon were studied by Deep Level Transient Spectroscopy (DLTS). Two different sets of samples were used which differ in the Ir-doping process. Stable Ir isotopes were introduced in the melt during the floating-zone growth process. Other samples were implanted with radioactive mercury isotopes, which decay via gold and platinum to iridium or osmium. In these samples an identification of Ir-related levels from the known half-life of the isotopes is possible. Two dominant levels at E c - 0.28 eV and E c - ().57 eV are assigned to isolated substitutional Ir. Two other levels at E c - 0.17 eV and E c - 0.45 eV are identified as iridium-hydrogen complexes containing one or two hydrogen atoms, respectively.

Aluminium-doped p-type (Al-p+) silicon emitters fabricated by means of a simple screen-printing process are effectively passivated by plasma-enhanced chemical-vapour deposited amorphous silicon (a-Si). We measure an emitter saturation current density of only 246 fA/cm2, which is the lowest value achieved so far for a simple screen-printed Al-p+ emitter on silicon. In order to demonstrate the applicability of this easy-to-fabricate p+ emitter to high-efficiency silicon solar cells, we implement our passivated p+ emitter into an n+np+ solar cell structure. An independently confirmed conversion efficiency of 19.7% is achieved using n-type phosphorus-doped Czochralski-grown silicon as bulk material, clearly demonstrating the high-efficiency potential of the newly developed a-Si passivated Al-p+ emitter. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The properties of a Pd—Au complex in n-type Si are investigated by DLTFS (deep level transient Fourier spectroscopy) techniques. In n-type Si the energy level of the Pd—Au complex is slightly shifted with isochronal annealing and does not display stable properties. The defect reaction of Pd—Au is explained by an “enhanced kick-out” mechanism represented by the reaction equation Aui + Pds Aus + Pdi, where interstitially diffusing gold replaces substitutional palladium. This reaction is similar to the Au—Rh defect reaction. The results of the investigations of the properties of the Pd—Au complex in p-type Si will be published later. Die elektrischen Eigenschaften des Pd—Au-Komplexes in n-Si werden mit dem DLTFS (deep level transient Fourier spectroscopy) Verfahren untersucht. Die Energieniveaus dieses Komplexes in n-Si verschieben sich bei Temperung und sind bei hohen Temperaturen nicht stabil. Die Pd—Au-Reaktion wird durch den “enhanced kick-out” Mechanismus erklart, der durch die Reaktionsgleichung Aui + Pds Aus + Pdi beschrieben wird, wobei interstitiell diffundierendes Gold substitutionelles Pd ersetzt. Diese Reaktion entspricht der Au—Rh-Reaktion. Die Ergebnisse der elektrischen Eigenschaften des Pd—Au-Komplexes in p-Si werden demnachst veroffentlicht.

In this study, back-contacted back-junction n-type silicon solar cells featuring a large emitter coverage (point-like base contacts), a small emitter coverage (point-like base and emitter contacts), and interdigitated metal fingers have been fabricated and analyzed. For both solar cell designs, a significant reduction of electrical shading losses caused by an increased recombination in the non-collecting base area on the rear side was obtained. Because the solar cell designs are characterized by an overlap of the B-doped emitter and the P-doped base with metal fingers of the other polarity, insulating thin films with excellent electrical insulation properties are required to prevent shunting in these overlapping regions. Thus, with insulating thin films, the geometry of the minority charge carrier collecting emitter diffusion and the geometry of the interdigitated metal fingers can be decoupled. In this regard, plasma-enhanced chemical vapor deposited SiO2 insulating thin films with various thicknesses and deposited at different temperatures have been investigated in more detail by metal-insulator-semiconductor structures. Furthermore, the influence of different metal layers on the insulation properties of the films has been analyzed. It has been found that by applying a SiO2 insulating thin film with a thickness of more than 1000 nm and deposited at 350 °C to solar cells fabricated on 1 Ω cm and 10 Ω cm n-type float-zone grown silicon substrates, electrical shading losses could be reduced considerably, resulting in excellent short-circuit current densities of more than 41 mA/cm2 and conversion efficiencies of up to 23.0%. Copyright © 2012 John Wiley & Sons, Ltd.

Combined resonance of the EDSR type is investigated with n-type silicon crystals plastically deformed under high stress. The signal is due to electrons oscillating along straight segments of 90° partial dislocations. The effect is closely related to microwave conductivity. Es wird uber EDSR-Spektren von n-Siliziumkristallen berichtet, die unter hoher Spannung plastisch verformt waren. Das Spektrum beruht auf der Oszillation von Elektronen entlang gerader Segmente von 90°-Partialversetzungen. Es besteht die gleiche Abhangigkeit von der effektiven Dotierung wie bei der Mikrowellenleitfahigkeit.

The variation in the nonequilibrium charge-carrier lifetime (τ) is studied under irradiation with 60Co γ-rays (Tirr ⪅ 50 °C) and subsequent isochronal annealing (Tann = 100 to 650 °C) of zone floated and pulled n-Si (ϱ ≈ 100 Ω cm) containing higher densities of dislocations introduced at plastic deformation (ND = 1 × 102 to 1 × 107 cm−2). τ is measured (Tmeas = 300 K) by the method of conductivity modulation at a point contact at different nonequilibrium charge-carrier injection levels. The regularities established of the τ-variation and its dependence on radiation-thermal treatments of the crystals studied are explained taking into account the interaction of radiation defects and their components, mobile under the experimental conditions, with dislocations. As a result, both the structure of the dislocations and thereby their recombination activity change. The presence of an impuritiy atmosphere near the dislocations is shown to prevent the rearrangement of the dislocation structure under irradiation but to facilitate it at annealing. [Russian Text Ignored.]

Electrical properties of deep levels introduced during quenching from high temperatures in VPE layers of n-type silicon are investigated. Two levels at 0.51 and 0.32 eV below the conduction band are found. The capture cross section of the deeper level is large (> 1.0 × 10−15 cm2). The capture cross section of the shallower level is of the order of 10−16 cm2 and has a T−2 dependence. It is suggested that the deeper level is due to the positively charged state and the shallower level to the neutral charge state of the same defect. The probable origin of the defect is the contamination by iron during wafer processing. The pressure coefficients of the energy levels and the electron capture cross sections are determined. Die elektrischen Eigenschaften von tiefen Niveaus, die wahrend der Abschreckung von hohen Temperaturen in n-leitenden VPE-Siliziumschichten eingefuhrt werden, werden untersucht. Zwei Niveaus bei 0,51 und 0,32 eV unterhalb des Leitungsbandes werden gefunden. Der Einfangquerschnitt des tieferen Niveaus ist gros (> 1,0 × 10−15 cm2). Der Einfangquerschnitt des flacheren Niveaus ist von der Gros enordnung 10−16 cm2 und hat eine T−2-Abhangigkeit. Es wird angenommen, das das tiefere Niveau von dem positiv geladenen Zustand und das flachere Niveau durch den neutralen Ladungszustand desselben Defekts hervorgerufen wird. Die wahrschcinliche Ursache des Defekts ist die Verunreinigung mit Eisen wahrend des Wafer-Prozesses. Die Druck-koeffizienten der Energieniveaus und der Elektroneneinfangquerschnitte werden bestimmt.

The tilted field method is used to measure the coincidence of spin-split Landau levels of different Landau quantum numbers in (100) n-type silicon inversion layers. At constant magnetic field perpendicular to the surface the peak values of Shubnikov-de Haas oscillations are analyzed as a function of the tilt angle ϕ, where ϕ is the angle between the surface normal and the magnetic field. Pronounced maxima of sxx for Corbino devices and of sxx for Hall devices are found at the coincidence condition. The electronic g-factor determined from the coincidence is substantially larger than the bulk value contrary to a recent publication, where experimental evidence for g = 2 was claimed. It is also shown that the Hall component does not falsify the results when the angular dependence of the resistivity maxima is investigated at constant total magnetic fields for a fixed Landau quantum number. An (100) n-Typ Silizium-Inversionsrandschichten wird durch Drehen der Probe im Magnetfeld die Koinzidenz spinaufgespaltener Landauniveaus mit unterschiedlicher Landauquantenzahl gemessen. Die Maximal werte der Shubnikov-de Haas-Oszillationen werden bei konstantem Magnetfeld senk-recht zur Oberflache als Funktion des Drehwinkels ϕ untersucht, wobei ϕ der Winkel zwischen der Oberflacheimormalen und dem Magnetfeld ist. Bei der Koinzidenz werden ausgepragte Maxima in sxx fur Corbino-Proben und in gxx fur Hall-Proben beobachtet. Der daraus bestimmte elektronische g-Faktor ist wesentlich groser als der Volumenwert im Gegensatz zu einer kurzlichen Veroffentlichung, in der die Autoren behaupten, den experimentellen Beweis fur g = 2 gefunden zu haben. Ferner wird gezeigt, das die Hallkomponente die Ergebnisse nicht verfalscht, wenn die Winkelabhangigkeit der Widerstandsmaxima bei konstantem Gesamtmagnetfeld fur eine feste Landauquantenzahl untersucht wird.

From capacitance measurements, the thermal capture cross-section of electrons at neutral gold centres is determined through the time dependence of the net ionized recombination centres concentration to σ = 1.24 × 10−16 (T/300)−(0.21 ± 0.03) cm2 in the temperature range 80 to 205 K. La section de capture thermique des electrons sur l'or neutre est deduite de la dependance temporelle de la densite de centres profonds ionises, mesuree par une technique capacitive. Pour le domaine de temperature 80 a 205 K le resultat est: σ = 1,24 × 10−16 (T/300)−(0,21 ± 0.03) cm2.

Deep level transient spectroscopy measurements on electron bombarded floating-zone n-Si Schottky diodes are reported. Activation energies and capture cross-sections of five observed majority-carrier traps (Ec – 0.15 eV, Ec – 0.21 eV, Ec – 0.28 eV, Ec – 0.33 eV, and Ec – 0.45 eV) are examined. Depth profiling and electric field effects on the thermal emission of the traps are also investigated. Identifications made by reference to the published literature are discussed. Es werden DLTS-Messungen an elektronenbestrahlten Schottkydioden aus n-leitendem zonengezogenem Si durchgefuhrt. Aktivierungsenergien und Einfangsquerschnitte von funf beobachteten Majoritatstragerhaftstellen (Ec – 0,15 eV, Ec – 0,21 eV, Ec – 0,28 eV, Ec – 0,33 eV und Ec – 0,45 eV) werden untersucht. Tiefenprofil und Einflusse des elektrischen Feldes auf die thermische Emission der Haftstellen werden ebenfalls untersucht. Die Identifizierung anhand der Literaturdaten wird diskutiert.

This paper describes investigations on process induced crystal defects in n-type silicon material of both Czochralski- and zone-floating-techniques (dislocation-free). The heating and cooling processes, the oxide thickness, mechanical stresses near the diffusion windows, the mask pattern geometry concerning diffusion and the surface concentration of the doping material have been specially investigated. The influence of those technological parameters on the generation of crystal defects in the production of electronic devices is investigated and discussed. Es wurden Untersuchungen zur prozesinduzierten Bildung von Strukturdefekten fur n-leitendes versetzungsfreies Czochralski- und zone-floating-Silizium durchgefuhrt. — Besondere Beachtung fanden die Aufheiz- und Abkuhlvorgange, die Oxidschichtdicke, mechanische Spannungen an den Deckschicht-Substratubergangen der Diffusionsfenster, Diffusionsmaskengeometrie und die Oberflachenkonzentration bei der Diffusion. Der Einflus der genannten technologischen Parameter auf die Bildung von Gefugedefekten im Bauelementeprozes wird untersucht und diskutiert.

The temperature independence of the capture cross-section of the neutral Au-acceptor level for electrons in silicon, σn, in the range of 172 to 316 K is found. The measurements were performed at high-resistivity, Au-compensated single-injection SCLC diodes by means of a pulse and a small-signal capacitance method. In der vorliegenden Arbeit wird die Temperaturunabhangigkeit des Wirkungsquerschnitts σn des neutralen Au-Akzeptorniveaus fur Elektronen in Silizium im Temperaturbereich 172 bis 316 K nachgewiesen. Die Messungen wurden an hochohmigen Au-kompensierten Einfachinjektions-SCLC-Dioden mit Hilfe einer Puls- und einer Kleinsignal-Kapazitatsmethode durchgefuhrt.

ESR linewidth, electronic g-value and ESR spin susceptibility of n-type silicon doped with phosphorus and arsenic are investigated at temperatures between 1.2 and 300 K near a metal-nonmetal transition. Temperature, impurity concentration, and donor dependences of the linewidths are discussed with regard to the spin relaxation mechanism in line-narrowing at low temperatures. ESR-Linienbreite, elektronischer g-Faktor und ESR-Spin-Suszeptibilitat von Phosphorund Arsen-dotiertem n-Silizium werden im Temperaturbereich von 1,2 bis 300 K in der Nahe des Metall-Isolator-Ubergangs untersucht. Die Abhangigkeit der Linienbreite von der Temperatur, der Konzentration der Verunreinigungen und der Art des Donators wird anhand der bei niedrigen Temperaturen vorliegenden Spin-Relaxations-Mechanismen diskutiert.

Measurements of the Faraday rotation in n-type silicon have been performed at room and at low (93 °K) temperatures. A crossed-waveguide technique (18.0 to 26.5 GHz), similar in principle (but in a simplified form) to the technique of Bouwknegt and Volger [4], has been used for the measurements. The rotation has been studied as a function of de magnetic field up to 10 kOe. The effect of multiple reflections has also been studied at low temperatures. The theory of the Faraday effect in anisotropic n-silicon, previously developed by the authors [3], is modified taking into account the contribution of mixed scattering of lattice and impurities. The modified theory is compared with the experiment, and an estimation is made of the relative importance of the impurity over the lattice scattering. It is shown that impurity scattering gives an appreciable contribution to the rotation. Bei Zimmertemperatur und niedrigeren Temperaturen (93 °K) wurden Messungen der Faraday-Rotation in n-leitendem Silizium durchgefuhrt. Eine Technik gekreuzter Hohl-leiter (18,0 bis 26,5 GHz), die im Prinzip der Technik von Bouwknegt und Volger [4], jedoch in vereinfachter Form, ahnlich ist, wurde fur die Messungen benutzt. Die Rotation wurde als Funktion des konstanten Magnetfeldes bis zu 10 kOe untersucht. Desgleichen wurde der Effekt der Mehrfachreflexionen bei niedrigen Temperaturen gemessen. Die Theorie des Faraday-Effekts im anisotropen, n-leitenden Silizium, die von den Autoren [3] entwickelt wurde, wird modifiziert und berucksichtigt den Beitrag der gemischten Streuung von Gitter und Storstellen. Die modifizierte Theorie wird mit dem Experiment verglichen und die relative Bedeutung der Storstellen-gegenuber der Gitterstreuung berechnet. Es wird gezeigt, das Storstellenstreuung einen bedeutenden Beitrag zur Drehung liefert.

Earlier measurements have been extended to a larger number of samples of high crystal-line perfection, high purity, and well-defined homogeneous doping. Furtheron the measuring equipment has been improved. The before madc statement could be confirmed, that the transverse electron mass as derived from the magnetic susceptibility in silicon–germaniuni alloys with a silicon content between 65 and 100 at% Si is constant with a value m⟂ = 0.27 m (m free electron mass). Fruliere Messungen wurden mit einer verbesserten expcrimentellen Anordnung auf eine grose Zahl von Proben ausgedehnt, die eine hohe Kristallqualitat. hohe Reinheit und hornogene wohldefinierte Dotierung besasen. DAS fruhere Ergebnis wurde bestlitigt : die transversale effektive Masse m, ⟂ = 027 m, wie sie sich aus der niagnetischen Suszeptibilitat ergibt, ist fur Silizium–Germanium-Legierungen mit einem Siliziamgehalt zwischeri 65 und 100 At% si konstant (m Masse des freien Elektrons).

The magnitude of the subband splitting in inversion layers was investigated with piezoresistance measurements of n-type inversion channels on (100) and (110) silicon surfaces. Below 70 K the piezoresistance effect is no longer linear with stress and surface field. At high tensile and compressive stress two saturation regions occur corresponding to the magnitude of the subband splitting. The experimental results were compared with several models describing surface quantization. A self-consistent calculation shows the best agreement, whereas the triangular potential well model deviates more than 100%. For a (100) transverse configuration an anomalous behaviour was observed which is explained in terms of different relaxation times in the various subbands. Es wurde die Grose der Subbandaufspaltungen in Inversionsschichten mit Piezowiderstandsmessungen von n-leitenden Inversionskanalen auf (100)- und (110)-Siliziumoberflachen untersucht. Unterhalb 70 K ist der Piezowiderstandseffekt nicht langer linear mit der Spannung und dem Oberflachenfeld. Bei hohen Dehnungs- und Kompressionsspannungen treten zwei Sattigungsbereiche auf, die der Grose der Subbandaufspaltung entsprechen. Die experimentellen Ergebnisse werden mit verschiedenen Modellen der Oberflachenquantisierung verglichen. Eine selbstkonsistente Berechnung zeigt die beste Ubereinstimmung, wahrend das Dreiecks-Potentialtopfmodell um mehr als 100% abweicht. Fur eine transversale (100)-Konfiguration wurde ein anomales Verhalten beobachtet, das mit unterschiedlichen Relaxationszeiten in den verschiedenen Subbandern erklart wird.

The theory of free carrier Faraday effect in anisotropic semiconductors, previously developed by Donovan and Webster [1,2], is extended to the case of n-type silicon. The high-frequency magnetoconductivity tensors are derived taking into account the detailed structure of conduction band. The Faraday rotation measurements in some [111] oriented samples of n-silicon are performed at room temperature and microwave frequencies. These results and the results of previous workers with different orientation of silicon samples, show reasonable agreement with the theory. Die fruher von Donovan und Webster [1,2] entwickelte Theorie des Faraday-Effekts freier Ladungstrager in anisotropen Halbleitern wird auf n-leitendes Silizium ausgedehnt. Die Tensoran der Magneto-Hochfrequenzleitfahigkeit werden abgeleitet, wobei die detaillierte Struktur des Leitungsbandes berucksichtigt wurde. Die Messungen der Faraday-Drehung werden in einigen in [111]-Richtung orientierten Proben von n-leitendem Silizium bei Zimmertemperatur und Mikrowellenfrequenzen durchgefuhrt. Diese Ergebnisse und Ergebnisse fruherer Autoren bei verschiedenen Orientierungen der Si-Proben zeigen befriedigende Ubereinstimmung mit der Theorie.

The factor relating the Hall coefficient to carrier concentration has been determined in n-type silicon by combining optical measurements of the carrier concentration at infrared frequencies with conventional dc Hall effect measurements. Interpreting this factor in terms of electronic charge, mobility anisotropy and the usual scattering constant, the latter is found to reach values much greater than unity, especially at 77 °K, when with a doping level of 2.6 × 1017 cm−3 a value of 7.3 is obtained. Fur n-leitendes Silizium wurde der Faktor bestimmt, der den Hall-Koeffizienten mit der Tragerkonzentration verknupft, indem optische Messungen der Tragerkonzentration bei Infrarot-Wellenlangen mit herkommlichen Gleichstrom-Halleffektrnessungen kombiniert wurden. Bei der Interpretation dieses Faktors hinsichtlich Elektronenladung, Anisotropie der Beweglichkeit sowie der ublichen Streukonstante ergeben sich fur die letztere Werte groser als eins; insbesondere wurde bei 77 °K und einer Dotierungskonzentration von 2,6 × 1017 cm−3 ein Wert von 7,3 gefunden.