Curved Solar Cell P-N Junction Exposure
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Solution Overview
Problem
Traditional silicon-based solar cells have low light absorbing efficiency due to partial photons being absorbed by the front electrode and N-type silicon layer, resulting in sparse carrier generation and low photoelectric conversion efficiency.
Innovation Solution
The method involves creating a round P-N junction preform with stacked silicon layers, cutting it into rectangular and arc-shaped solar cells, where the P-N junction is directly exposed on an arc-shaped surface, reducing light obstruction by electrodes and increasing the surface area for light absorption, thereby enhancing the photoelectric conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If light directly irradiates the front electrode and reaches the P-N junction through the front electrode and N-type silicon layer, then the solar cell structure is simple and easy to manufacture, but the light absorbing efficiency is low because partial photons are absorbed by the front electrode and N-type silicon layer
Solution Approach 1:
The patent extracts the front electrode and N-type silicon layer from the direct light path by introducing a reflective layer beneath the P-N junction. This allows light that passes through the P-N junction to be reflected back, giving photons a second chance to generate carriers without requiring the front electrode to be transparent or thin, thus maintaining manufacturing simplicity while improving light absorption.
Solution Approach 2:
The reflective layer creates a periodic light path where photons that transmit through the P-N junction are reflected back to interact with the junction again. This periodic interaction increases the probability of photon absorption and carrier generation without complicating the basic cell structure.
2Loss of energy
If the P-N junction is directly exposed to light, then the photoelectric conversion efficiency increases, but the device structure becomes more complex
Solution Approach 1:
The patent addresses the structural complexity issue by adding a reflective layer in the vertical dimension beneath the P-N junction, rather than complicating the front surface geometry. This dimensional addition allows direct light exposure to the P-N junction while maintaining a relatively simple overall structure through the reflection mechanism.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for improved light absorption and carrier generation, increasing the photoelectric conversion efficiency of the solar cells by directly exposing the P-N junction to incident light and minimizing reflection, leading to higher energy conversion rates.
Implementation Method 1
An operating principle of a solar cell is the photoelectric effect of a semiconducting material
Implementation Method 2
a plurality of electron-hole pairs (carriers) can be generated in the P-N junction due to photon excitation
Implementation Method 3
a reflective layer is provided behind the P-N junction... the transmitted light is reflected by the reflective layer
Implementation Method 4
an anti-reflective coating is formed on a surface of the solar cell
Implementation Method 5
Electrons and holes in the electron-hole pairs can be separated from each other and separately move toward the rear electrode and the front electrode under an electrostatic potential
Data Source
AI summary
A solar cell includes an integrated structure. The integrated structure includes a first electrode layer, a P-type silicon layer, an N-type silicon layer, and a second electrode layer arranged in the above sequence. At least one curved surface is defined on the integrated structure. The integrated structure includes a P-N junction near an interface between the P-type silicon layer and the N-type silicon layer; and a photoreceptive surface exposing the P-N junction. The photoreceptive surface is one the at least one curved surface of the integrated structure and is configured to receive incident light beams.