Photovoltaic Characterization of Trapping in Porous Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
D. W. Boeringer ◽  
R. Tsu

ABSTRACTWe report the first observation of the lateral photovoltaic effect in porous silicon. Contacts placed on either side of a porous silicon region develop a voltage up to several millivolts if the sample is asymmetrically illuminated. If the light spot is closer to one contact, the voltage will have one polarity; if it is closer to the other contact, the polarity will be opposite. In the case of n-type, the contact nearest the light spot is positive; for p-type, the contact nearest the light spot is negative In the region between the contacts, the photovoltage varies almost linearly with the position of the light spot, over a distance 4.5 cm across. The origin of our lateral photoeffect may be explained by the trapping of photoexcited carriers by a pair of dangling bond centers in porous silicon. In the case of p-type, the photogenerated electrons are trapped by the dangling bond states while holes diffuse away in the substrate. The situation for n-type is opposite; holes are trapped by the dangling bond states while electrons diffuse away in the substrate. This differs from the conventional lateral photoeffect, which arises under the nonuniform illumination of a junction between two layers of differing conductivities. Hamamatsu sells silicon-based position-sensitive detectors with a resolution down to 0.1 µm. The possibility of using this lateral photoeffect to characterize these dangling bond states in porous silicon as well as several possible device applications will be discussed.

1995 ◽  
Vol 405 ◽  
Author(s):  
D. Dimova-Malinovska ◽  
M. Tzolov ◽  
M. Kamenova ◽  
N. Tzenov ◽  
M. Sendova-Vassileva ◽  
...  

AbstractThe results of photoelectric properties and electroluminescent studies of structures ZnO/porous Si/p-type c-Si/Al and ZnO/porous Si/p-n c-Si junction/Al are presented. Porous Si is prepared by stain etching of c-Si covered with thin Al film. The transparent ZnO film allows light emission through the top surface of the device under forward electrical bias. Photocurrent is observed under reverse bias and a photovoltaic effect is measured on the p-n junction PS device. The model based on injection of minority carriers through a narrow energy barrier into the porous Si and the presence of the barrier at the interface porous Si/c-Si is suggested for describing the electrical, photoelectric and luminescent properties of the structures.


1984 ◽  
Vol 33 ◽  
Author(s):  
R. C. Frye

ABSTRACTPorous silicon is formed by the anodic dissolution of p-type silicon in aqueous hydrofluoric acid. Because of its very high porosity, this material can be rapidly cKidized to form thick (˜10 μn) oxide layers with minimal stress on the underlying silicon wafer. A remarkable property of porous silicon is that preserves the crystalline orientation of the substrate despite removal of more than half of the silicon in the etched region, providing a suitable surface for the growth of epitaxial layers. Several schemes for dielectric isolation have been suggested which take advantage of these unique properties. In this paper, the mechanism of porous silicon formation will be presented and the relative advantages and disadvantages for practical device applications will be discussed.


2009 ◽  
Vol 609 ◽  
pp. 11-25
Author(s):  
Emil Pinčík ◽  
Hikaru Kobayashi ◽  
Róbert Brunner ◽  
Masao Takahashi ◽  
Jaroslav Rusnák ◽  
...  

The paper presents results of research of similar electrical, optical and structural properties of three types of MOS structures prepared on different Si-based semiconductors. Electrical interface properties are investigated by institutionally produced equipment with Charge Version of Deep Level Transient Spectroscopy and time domain C-V. X-ray diffraction at grazing incidence angles is applied to control their structural properties. Optical properties of selected structures are investigated by photoluminescence measurements at liquid helium temperature (approx. 6K in cryostat). Dominant interest is focused on analysis of both electrical properties of MOS porous silicon based structures prepared on p-type crystalline Si and photoluminescence signals of the structures observed around 1.1 eV, respectively. Such parameters as Fermi level position, flat-band voltage, surface potential, position of deep level hole traps, and acceptor density are calculated for various conditions as defined by sample ambient, temperature, and light illumination. Following two main findings are analyzed: i) total suppression of large C-V hysteresis due to suitable illumination and ii) recovering of part of detected interface states in the dark.


1992 ◽  
Vol 283 ◽  
Author(s):  
M. J. Heben ◽  
Y. S. Tsuo

ABSTRACTWe present results from our investigations of the transport properties of p-type Si/porous silicon/Au devices. Current-voltage measurements were performed as a function of temperature from room temperature down to 23K and indicate that a tunneling mechanism governs the transport properties of these devices. Photocurrent spectroscopy measurements were performed as a function of temperature and excitation wavelength and support the conclusion that a tunneling mechanism is operative in these devices. The external quantum efficiencies of our porous-silicon-based structures can be greater than 20%, and the shape of the photocurrent spectra of porous-silicon-based devices, when compared to that of a p-type Si/Au diode, suggests that carriers photogenerated within porous silicon can be collected in an external circuit.


2018 ◽  
Vol 386 ◽  
pp. 137-142
Author(s):  
Tatiana A. Pisarenko ◽  
Vyacheslav V. Balashev ◽  
Vladimir V. Korobtsov ◽  
Artem A. Dimitriev ◽  
Victor A. Vikulov

We report on the results of the study of the lateral photovoltaic effect in the Fe/SiO2/Si structures with n-and p-type silicon. It is found that in both cases the photovoltage signal varies linearly when the light spot moves between the electrodes. It is established that the sensitivity of lateral photovoltaic effect in Fe/SiO2/n-Si and Fe/SiO2/р-Si structures is 32.3 and 14.7 mV/mm, respectively. When the silicon conductivity type changes, there is an inversion of photovoltage polarity as a result of the opposite direction of the built-in electrical field at the SiO2/Si interface. It was found that the response time in the Fe/SiO2/n-Si structure is 4.2 times faster than in the Fe/SiO2/p-Si structure due to the presence of an inversion layer in this structure.


1993 ◽  
Vol 298 ◽  
Author(s):  
Shulin Zhang ◽  
Kuoksan He ◽  
Yangtian Hou ◽  
Xin Wang ◽  
Jingjian Li ◽  
...  

AbstractA novel step—like and pinning behavior of photoluminescence peak energy connected with changes in the concentration of HIF and current density were for the first time observed for p— type porous silicon. Based on a theoretical calculation of the electron structure of the silicon quantum wire it is argued that these behaviors can be explained in terms of a novel formation mechanism model of porous silicon.


2010 ◽  
Vol 663-665 ◽  
pp. 836-839 ◽  
Author(s):  
Yuan Ming Huang ◽  
Qing Lan Ma ◽  
Ming Meng ◽  
Bao Gai Zhai

The primary aim of this communication is to introduce a novel approach of preparation of solar cell, viz. PS based solar cell, which is on the basis of the basic principle of the well established photovoltaic effect. We carefully investigate the current-voltage characteristics of the PS-based solar cell by virtue of performing the measurement of both current and voltage of PS-based solar cell under the condition of the sunlight irradiation and priori to sunlight irradiation in the purpose of observing clearly the photovoltaic effect possessed by the PS based solar cell. Judging by the results obtained in this paper, we can safely draw the conclusion that porous silicon is a good candidate material for the preparation of solar cell, that is to say that our study is giving high hope for the industrial production of high efficient PS-based thin film solar cells.


2007 ◽  
Vol 556-557 ◽  
pp. 153-156
Author(s):  
Chi Kwon Park ◽  
Gi Sub Lee ◽  
Ju Young Lee ◽  
Myung Ok Kyun ◽  
Won Jae Lee ◽  
...  

A sublimation epitaxial method, referred to as the Closed Space Technique (CST) was adopted to produce thick SiC epitaxial layers for power device applications. In this study, we aimed to systematically investigate surface morphologies and electrical properties of SiC epitaxial layers grown with varying a SiC/Al ratio in a SiC source powder during the sublimation growth using the CST method. It was confirmed that the acceptor concentration of epitaxial layer was continuously decreased with increasing the SiC/Al ratio. The blue light emission was successfully observed on a PN diode structure fabricated with the p-type SiC epitaxial layer. Furthermore, 4H-SiC MESFETs having a micron-gate length were fabricated using a lithography process and their current-voltage performances were characterized.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Tero Jalkanen ◽  
Anni Määttänen ◽  
Ermei Mäkilä ◽  
Jaani Tuura ◽  
Martti Kaasalainen ◽  
...  

A roll-to-roll compatible fabrication process of porous silicon (pSi) based sensing elements for a real-time humidity monitoring is described. The sensing elements, consisting of printed interdigitated silver electrodes and a spray-coated pSi layer, were fabricated on a coated paper substrate by a two-step process. Capacitive and resistive responses of the sensing elements were examined under different concentrations of humidity. More than a three orders of magnitude reproducible decrease in resistance was measured when the relative humidity (RH) was increased from 0% to 90%. A relatively fast recovery without the need of any refreshing methods was observed with a change in RH. Humidity background signal and hysteresis arising from the paper substrate were dependent on the thickness of sensing pSi layer. Hysteresis in most optimal sensing element setup (a thick pSi layer) was still noticeable but not detrimental for the sensing. In addition to electrical characterization of sensing elements, thermal degradation and moisture adsorption properties of the paper substrate were examined in connection to the fabrication process of the silver electrodes and the moisture sensitivity of the paper. The results pave the way towards the development of low-cost humidity sensors which could be utilized, for example, in smart packaging applications or in smart cities to monitor the environment.


1998 ◽  
Vol 84 (6) ◽  
pp. 3129-3133 ◽  
Author(s):  
S. Setzu ◽  
G. Lérondel ◽  
R. Romestain

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