Skip to main content Accessibility help
×
Home
Hostname: page-component-8bbf57454-wdwc2 Total loading time: 0.22 Render date: 2022-01-23T09:35:15.586Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "metricsAbstractViews": false, "figures": true, "newCiteModal": false, "newCitedByModal": true, "newEcommerce": true, "newUsageEvents": true }

Analysis of Tunnel Junction Suitable for 4000 Suns in Tandem High Efficiency Solar Cell Structures

Published online by Cambridge University Press:  31 January 2011

Donggeun Jung
Affiliation:
djung@skku.ac.kr, Sungkyunkwan University, Department of Physics, Seoul, Korea, Republic of
Conrad Zachary Carlin
Affiliation:
czcarlin@ncsu.edu
John R. Hauser
Affiliation:
bedair@ncsu.edu, North Carolina State University, Electrical and Computer Engineering, Raleigh, North Carolina, United States
Salah M. Bedair
Affiliation:
hauser@ncsu.edu, North Carolina State University, Electrical and Computer Engineering, Raleigh, North Carolina, United States
Get access

Abstract

The road to achieve ultra high efficiency is through multi-junction solar cells operating at high solar concentrations, larger than 1000 suns. Critical to the success of this approach is the development of tunnel junctions (TJ) that serve as electrically low loss interconnections, yet are optically transparent, using high band gap semiconductor material systems. We have previously reported the fabrication of a TJ made of n+-InGaP/ p+-AlGaAs with a band gap about 1.9 eV using Se and C doping, respectively. This TJ structure has a peak current density of 88 A/cm2 allowing it to be implemented in a three junction cell structure at solar concentrations as high as 4000 suns (x4000). Almost all reported conversion efficiencies higher than 40% have used this tunnel junction. This very high peak current density is unexpected in a high band gap material system, which is good news for the multi junction solar community. This seems to be due to the fact that the InGaP/AlGaAs interface has a staggered band line up. We will present the effect of this band line up at the heterointerface and its effect on the width of the depletion region and the peak current density. We also compare the current result from this heterostructure junction with an artificial homojunction made of n+-AlGaAs/ p+-AlGaAs doped to the same levels as that of the heterojunction. Results from the homojunction showed that peak current density is about one half of that obtained from the heterojunction at the same doping levels. A reasonable match between experimental result and the model was obtained when a value of 150 meV was used for ΔEc, the conduction band discontinuity at the interface. Both experiment and theory predicted that at a current density of about 80 A/cm2 with only about a few tens of meV drop across the TJ. This will have a minimal effect on the overall efficiency of the tandem solar cell structure when used at high solar concentrations.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Bedair, S. M. Lamorte, M. F. and Hauser, J. R. Appl. Phys. Lett. 34, 38 (1979).Google Scholar
2 Jung, D. Parker, C. A. Ramdani, J. and Bedair, S. M. J. Appl. Phys. 74, 2090 (1993).CrossRefGoogle Scholar
3 Konagai, M. Yamada, T. Akatsuka, T. Saito, K. Tokumitsu, E. and Takahashi, K. J. Cryst. Growth 98, 167 (1989).CrossRefGoogle Scholar
4 Kobayashi, N. Makimoto, T. and Horikoshi, Y. Appl. Phys. Lett. 50, 1435 (1987).CrossRefGoogle Scholar
5 Anderson, R. L. Solid State Electron. 5, 341 (1962).CrossRefGoogle Scholar
6 Haase, M. A. Hafich, M. J. and Robinson, G. Y. Appl. Phys. Lett. 58, 616 (1991).CrossRefGoogle Scholar
7 Sze, S. M. Physics of Semiconductor Devices, 2nd Edition, New York: Wiley (1981), Chap. 9.Google Scholar
8 Basmaji, P. Guittard, M. Rudra, A. Carlin, J. F. and Gibart, P. J. Appl. Phys. 62, 2103 (1987).CrossRefGoogle Scholar
9 Rao, M. A. Caine, E. J. Kroemer, H. Long, S. I. and Babic, D. I. J. Appl. Phys. 61, 643 (1987).CrossRefGoogle Scholar

Send article to Kindle

To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Analysis of Tunnel Junction Suitable for 4000 Suns in Tandem High Efficiency Solar Cell Structures
Available formats
×

Send article to Dropbox

To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

Analysis of Tunnel Junction Suitable for 4000 Suns in Tandem High Efficiency Solar Cell Structures
Available formats
×

Send article to Google Drive

To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

Analysis of Tunnel Junction Suitable for 4000 Suns in Tandem High Efficiency Solar Cell Structures
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *