Minimum Effect of Non-Infinitesmal Intermediate Band Width on the Detailed Balance Efficiency of an Intermediate Band Solar Cell

AbstractIt has long been recognized that the introduction of a narrow band of states in a semiconductor band gap could be used to achieve improved power conversion efficiency in semiconductor-based solar cells. The intermediate band would serve as a “stepping stone” for photons of different energy to excite electrons from the valence to the conduction band. An important advantage of this design is that it requires formation of only a single p-n junction, which is a crucial simplification in comparison to multijunction solar cells. A detailed balance analysis predicts a limiting efficiency of more than 50% for an optimized, single intermediate band solar cell. This is higher than the efficiency of an optimized two junction solar cell. Using ion beam implantation and pulsed laser melting we have synthesized Zn1-yMnyOxTe1-x alloys with x<0.03. These highly mismatched alloys have a unique electronic structure with a narrow oxygen-derived intermediate band. The width and the location of the band is described by the Band Anticrossing model and can be varied by controlling the oxygen content. This provides a unique opportunity to optimize the absorption of solar photons for best solar cell performance. We have carried out systematic studies of the effects of the intermediate band on the optical and electrical properties of Zn1-yMnyOxTe1-x alloys. We observe an extension of the photovoltaic response towards lower photon energies, which is a clear indication of optical transitions from the valence to the intermediate band.

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Beneficial impact of a thin tunnel barrier in quantum well intermediate-band solar cell

EPJ Photovoltaics ◽

10.1051/epjpv/2018009 ◽

2018 ◽

Vol 9 ◽

pp. 11 ◽

Cited By ~ 2

Author(s):

Nicolas Cavassilas ◽

Daniel Suchet ◽

Amaury Delamarre ◽

Fabienne Michelini ◽

Marc Bescond ◽

...

Keyword(s):

Solar Cell ◽

Quantum Well ◽

Quantum Transport ◽

Detailed Balance ◽

Balance Model ◽

Tunnel Barrier ◽

Optical Coupling ◽

Intermediate Band ◽

Intermediate Band Solar Cell ◽

Beneficial Impact

Based on electronic quantum transport modeling, we study the transition between the intermediate-band and the conduction-band in nano-structured intermediate-band solar cell. We show that a tunnel barrier between the quantum well (QW) and the host material could improve the current. The confinement generated by such a barrier favors the inter-subband optical coupling in the QW and then changes the excitation-collection trade-off. More surprisingly, we also show that tunneling impacts the radiative recombination and then the voltage. Using a detailed balance model we explain and we propose a broadening factor for this Voc modification. Finally we show that a thin tunnel barrier is beneficial for both current and voltage.

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Numerical Investigation into Photovoltaic Performance of Organolead Trihalide Perovskite Quantum Dot Intermediate Band Solar Cell

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1048.172 ◽

2022 ◽

Vol 1048 ◽

pp. 172-181

Author(s):

Sourav Roy ◽

Md. Shohanur Rahman ◽

Diponkar Kundu ◽

Farhana Akter Piata ◽

Md. Rafiqul Islam

Keyword(s):

Solar Cell ◽

Energy Gap ◽

Photovoltaic Performance ◽

Detailed Balance ◽

Open Circuit ◽

Transport Layer ◽

Face Centered Cubic ◽

Intermediate Band ◽

Intermediate Band Solar Cell ◽

The Impact

In this work, an intermediate band solar cell (IBSC) model consisting of MAPbI3 quantum dots (QD) and MAPbCl3 barrier material is explored analytically with MATLAB. Titanium di-oxide (TiO2) is used as transport layer for electron and Spiro-OMeTAD (2,2',7,7'-tet-rakis (N,N'-di-p-methoxyphenylamine)–9,9' spirobifluorene) is used as transport layer for hole. Fluorine-doped tin oxide (FTO) and Silver (Ag) is used as top and bottom contact. The impact of QD size and dot spacing on the key parameters of MAPbI3 QD-IBSC is illustrated throughout this paper. In order to identify the number of IB in a single regime, Schrödinger equation is solved as a function of host energy gap using Kronig–Penney model. The detailed balance limit assumptions with unity fill factor are applied to extract highest efficiency from the system. For any case, face centered cubic (FCC) crystal structure is assumed. The (100) crystal orientation is considered as charge carriers from n–region to p–region transport in this orientation. Major performance indicators of the device such as photocurrent intensity Jsc, open circuit voltage Voc and power conversion efficiency η have been delineated. Highest efficiency of 63% is attained for dot size of 4 nm and dot spacing of 1.5 nm.

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