Transient absorption spectrometer using excitation by pulse current

A transient absorption spectrometer using excitation by a pulse current, comprising:

• a central control unit configured to send a trigger signal;
• a pulse generator configured to generate a current pulse signal under an action of a first trigger signal sent by the central control unit, wherein the current pulse signal is applied to a sample to be tested such that the sample is in a non-luminous excited state for single-carrier injection or a luminous excited state for luminescence in which an electroluminescent signal is generated;
• a laser configured to emit a pulsed optical signal under an action of a second trigger signal sent by the central control unit;
• a beam splitter disposed in a light-exiting direction of the laser, and configured to split the pulsed optical signal into a detection optical signal and a reference optical signal, wherein the detection optical signal irradiates the sample to be tested to generate a detected optical signal;
• a data acquisition unit configured to acquire, under an action of a third trigger signal and a fourth trigger signal sent by the central control unit, the electroluminescent signal, the detected optical signal and the reference optical signal regarded as a process to obtain electrical signal data indicating, at a single time instant, absorption intensities of the sample for optical signals of different wavelengths;
• and
• a data processing and imaging unit configured to process the electrical signal data to obtain a transient absorption signal of the sample to be tested and perform imaging,
• wherein the sample to be tested is an electro-excited sample, and the sample to be tested is placed on a sample table and connected to an output port of the pulse generator,
• wherein the current pulse signal is applied to the sample to be tested such that the sample is in the non-luminous excited state for single-carrier injection or a luminous excited state by electro-excitation in which an electroluminescent signal is generated, and
• wherein the sample to be tested is excited by using a current pulse signal having a frequency of ½ times of the frequency of the first trigger signal sent by the central control unit,
• a first current value of the sample to be tested in the excited state by electro-excitation without using irradiation by the detection optical signal is measured by an ammeter,
• a second current value of the sample to be tested in the excited state by electro-excitation using irradiation by the detection optical signal is measured by the ammeter, and
• a shape and a sequence of current pulses are adjusted based on a ratio of the first current value to the second current value, such that a ratio of an amplitude of an even-numbered current pulse signal to an amplitude of an odd-numbered current pulse signal is equal to the ratio of the first current value to the second current value.