Perovskite Materials for Energy and Environmental Applications

Здесь есть возможность читать онлайн «Perovskite Materials for Energy and Environmental Applications» — ознакомительный отрывок электронной книги совершенно бесплатно, а после прочтения отрывка купить полную версию. В некоторых случаях можно слушать аудио, скачать через торрент в формате fb2 и присутствует краткое содержание. Жанр: unrecognised, на английском языке. Описание произведения, (предисловие) а так же отзывы посетителей доступны на портале библиотеки ЛибКат.

Perovskite Materials for Energy and Environmental Applications: краткое содержание, описание и аннотация

Предлагаем к чтению аннотацию, описание, краткое содержание или предисловие (зависит от того, что написал сам автор книги «Perovskite Materials for Energy and Environmental Applications»). Если вы не нашли необходимую информацию о книге — напишите в комментариях, мы постараемся отыскать её.

PEROVSKITE MATERIALS FOR ENERGY AND ENVIRONMENTAL APPLICATIONS
The book provides a state-of-the-art summary and discussion about the recent progress in the development and engineering of perovskite solar cells materials along with the future directions it might take.
Audience

Perovskite Materials for Energy and Environmental Applications — читать онлайн ознакомительный отрывок

Ниже представлен текст книги, разбитый по страницам. Система сохранения места последней прочитанной страницы, позволяет с удобством читать онлайн бесплатно книгу «Perovskite Materials for Energy and Environmental Applications», без необходимости каждый раз заново искать на чём Вы остановились. Поставьте закладку, и сможете в любой момент перейти на страницу, на которой закончили чтение.

Тёмная тема
Сбросить

Интервал:

Закладка:

Сделать

The elementary equations for the operation of semiconductor-based devices describe the static and dynamic carrier behavior in semiconductors under external factors, like optical excitation or applied field, both causing deviations from conditions of thermal equilibrium.

Poisson’s Equation

The electric potential is related to the density of the space-charge by Poisson equation:

(1.31) Perovskite Materials for Energy and Environmental Applications - изображение 26

where ψ represents the electrostatic potential, the local permittivity is given by ε , and ρ represents the density of the local space charge.

The total contribution from all charges which may be mobile or fixed, including holes, electrons and ionized impurities is expressed as local space charge density.

(1.32) Where the elementary charge is given by q n gives the electron concentration - фото 27

Where the elementary charge is given by q , n gives the electron concentration, p represents the concentration of holes, Na is the concentration of ionized acceptors and Nd is the concentration of ionized donor.

The electric field is obtained by the gradient of the potential as:

(1.33) картинка 28

Continuity equations

When the electric fields and density gradients are present, the equation of continuity describes the behavior of excess carriers with time and in space:

(1.34) 135 where electron and hole concentrations are represented by n and p - фото 29

(1.35) where electron and hole concentrations are represented by n and p respectively - фото 30

where electron and hole concentrations are represented by n and p respectively. Jn and Jp are the electron current density and hole current density, Gn and Gp are the electrons and hole generation rates, Rn and Rp are the electron and hole recombination rates.

In steady state картинка 31and картинка 32.

Current density equations

Derivations focused on the transport theory given by Boltzmann have depicted that the current densities can be approximated in the continuity equations by the drift-diffusion model. In the present case, of the quasi Fermi levels EFn and EFp express the current densities:

(1.36) Perovskite Materials for Energy and Environmental Applications - изображение 33

(1.37) Perovskite Materials for Energy and Environmental Applications - изображение 34

Where μn and μp are the mobilities of the electrons and holes. The quasi-Fermi levels are linked to the carrier concentrations and the potential through the two Boltzmann approximations as follows:

(1.38) 139 To describe the quasiFermi levels these two equations may then be - фото 35

(1.39) To describe the quasiFermi levels these two equations may then be rewritten - фото 36

To describe the quasi-Fermi levels these two equations may then be rewritten as:

(1.40) 141 By putting these equations into the expression for current density - фото 37

(1.41) By putting these equations into the expression for current density the - фото 38

By putting these equations into the expression for current density, the following current relationships can be attained:

(1.42) 143 Where Dn and Dp represent the electron and hole diffusion constants - фото 39

(1.43) Perovskite Materials for Energy and Environmental Applications - изображение 40

Where Dn and Dp represent the electron and hole diffusion constants, respectively:

(1.44) Perovskite Materials for Energy and Environmental Applications - изображение 41

(1.45) Perovskite Materials for Energy and Environmental Applications - изображение 42

The final term in (1.42)and (1.43)reflects the difference in the effective concentration of the intrinsic carriers, taking into account the decreasing influence of the band-gap. Defining active electrical fields:

(1.46) 147 The driftdiffusion equations can then be written in more conventional - фото 43

(1.47) The driftdiffusion equations can then be written in more conventional form as - фото 44

The drift-diffusion equations can then be written in more conventional form as.

(1.48) 149 Optical generation of electronhole pairs It is necessary to the - фото 45

(1.49) Optical generation of electronhole pairs It is necessary to the operation of - фото 46

Optical generation of electron-hole pairs

It is necessary to the operation of solar cells to produce electron-hole pairs by absorbing sunlight. Holes and electrons lead to the transition of energy carried by the photons of light into electrical energy.

The number of incident photons S 0(ν) (per unit area, per unit time and per unit energy) determine the number of generated electron-hole pairs. The photon flux S ( x , ν) decreases inside the semiconductor exponentially as:

(1.50) where ν is the frequency The absorption process in the semiconductor - фото 47

where ν is the frequency. The absorption process in the semiconductor determines the absorption coefficient α (ν).

Читать дальше
Тёмная тема
Сбросить

Интервал:

Закладка:

Сделать

Похожие книги на «Perovskite Materials for Energy and Environmental Applications»

Представляем Вашему вниманию похожие книги на «Perovskite Materials for Energy and Environmental Applications» списком для выбора. Мы отобрали схожую по названию и смыслу литературу в надежде предоставить читателям больше вариантов отыскать новые, интересные, ещё непрочитанные произведения.


Отзывы о книге «Perovskite Materials for Energy and Environmental Applications»

Обсуждение, отзывы о книге «Perovskite Materials for Energy and Environmental Applications» и просто собственные мнения читателей. Оставьте ваши комментарии, напишите, что Вы думаете о произведении, его смысле или главных героях. Укажите что конкретно понравилось, а что нет, и почему Вы так считаете.

x